Docs Help

Terms, Icons, and Labels

Many classes have shortcut names used when creating (instantiating) a class with a configuration object. The shortcut name is referred to as an alias (or xtype if the class extends Ext.Component). The alias/xtype is listed next to the class name of applicable classes for quick reference.

Access Levels

Framework classes or their members may be specified as private or protected. Else, the class / member is public. Public, protected, and private are access descriptors used to convey how and when the class or class member should be used.

Member Types

Member Syntax

Below is an example class member that we can disect to show the syntax of a class member (the lookupComponent method as viewed from the Ext.button.Button class in this case).

lookupComponent ( item ) : Ext.Component
protected

Called when a raw config object is added to this container either during initialization of the items config, or when new items are added), or {@link #insert inserted.

This method converts the passed object into an instanced child component.

This may be overridden in subclasses when special processing needs to be applied to child creation.

Parameters

item :  Object

The config object being added.

Returns
Ext.Component

The component to be added.

Let's look at each part of the member row:

Member Flags

The API documentation uses a number of flags to further commnicate the class member's function and intent. The label may be represented by a text label, an abbreviation, or an icon.

Class Icons

- Indicates a framework class

- A singleton framework class. *See the singleton flag for more information

- A component-type framework class (any class within the Ext JS framework that extends Ext.Component)

- Indicates that the class, member, or guide is new in the currently viewed version

Member Icons

- Indicates a class member of type config

- Indicates a class member of type property

- Indicates a class member of type method

- Indicates a class member of type event

- Indicates a class member of type theme variable

- Indicates a class member of type theme mixin

- Indicates that the class, member, or guide is new in the currently viewed version

Class Member Quick-Nav Menu

Just below the class name on an API doc page is a row of buttons corresponding to the types of members owned by the current class. Each button shows a count of members by type (this count is updated as filters are applied). Clicking the button will navigate you to that member section. Hovering over the member-type button will reveal a popup menu of all members of that type for quick navigation.

Getter and Setter Methods

Getting and setter methods that correlate to a class config option will show up in the methods section as well as in the configs section of both the API doc and the member-type menus just beneath the config they work with. The getter and setter method documentation will be found in the config row for easy reference.

History Bar

Your page history is kept in localstorage and displayed (using the available real estate) just below the top title bar. By default, the only search results shown are the pages matching the product / version you're currently viewing. You can expand what is displayed by clicking on the button on the right-hand side of the history bar and choosing the "All" radio option. This will show all recent pages in the history bar for all products / versions.

Within the history config menu you will also see a listing of your recent page visits. The results are filtered by the "Current Product / Version" and "All" radio options. Clicking on the button will clear the history bar as well as the history kept in local storage.

If "All" is selected in the history config menu the checkbox option for "Show product details in the history bar" will be enabled. When checked, the product/version for each historic page will show alongside the page name in the history bar. Hovering the cursor over the page names in the history bar will also show the product/version as a tooltip.

Search and Filters

Both API docs and guides can be searched for using the search field at the top of the page.

On API doc pages there is also a filter input field that filters the member rows using the filter string. In addition to filtering by string you can filter the class members by access level, inheritance, and read only. This is done using the checkboxes at the top of the page.

The checkbox at the bottom of the API class navigation tree filters the class list to include or exclude private classes.

Clicking on an empty search field will show your last 10 searches for quick navigation.

API Doc Class Metadata

Each API doc page (with the exception of Javascript primitives pages) has a menu view of metadata relating to that class. This metadata view will have one or more of the following:

Expanding and Collapsing Examples and Class Members

Runnable examples (Fiddles) are expanded on a page by default. You can collapse and expand example code blocks individually using the arrow on the top-left of the code block. You can also toggle the collapse state of all examples using the toggle button on the top-right of the page. The toggle-all state will be remembered between page loads.

Class members are collapsed on a page by default. You can expand and collapse members using the arrow icon on the left of the member row or globally using the expand / collapse all toggle button top-right.

Desktop -vs- Mobile View

Viewing the docs on narrower screens or browsers will result in a view optimized for a smaller form factor. The primary differences between the desktop and "mobile" view are:

Viewing the Class Source

The class source can be viewed by clicking on the class name at the top of an API doc page. The source for class members can be viewed by clicking on the "view source" link on the right-hand side of the member row.

Ext JS 6.5.0 - Modern Toolkit


top

Hierarchy

Array

Summary

In JavaScript, the Array property of the global object is a constructor for array instances.

An array is a JavaScript object. Note that you shouldn't use it as an associative array, use Object instead.

Creating an Array

The following example creates an array, msgArray, with a length of 0, then assigns values to msgArray[0] and msgArray[99], changing the length of the array to 100.

var msgArray = new Array();
msgArray[0] = "Hello";
msgArray[99] = "world";

if (msgArray.length == 100)
print("The length is 100.");

Creating a Two-dimensional Array

The following creates chess board as a two dimensional array of strings. The first move is made by copying the 'P' in 6,4 to 4,4. The position 4,4 is left blank.

var board =
[ ['R','N','B','Q','K','B','N','R'],
['P','P','P','P','P','P','P','P'],
[' ',' ',' ',' ',' ',' ',' ',' '],
[' ',' ',' ',' ',' ',' ',' ',' '],
[' ',' ',' ',' ',' ',' ',' ',' '],
[' ',' ',' ',' ',' ',' ',' ',' '],
['p','p','p','p','p','p','p','p'],
['r','n','b','q','k','b','n','r']];
print(board.join('\n') + '\n\n');

// Move King's Pawn forward 2
board[4][4] = board[6][4];
board[6][4] = ' ';
print(board.join('\n'));

Here is the output:

R,N,B,Q,K,B,N,R
P,P,P,P,P,P,P,P
 , , , , , , ,
 , , , , , , ,
 , , , , , , ,
 , , , , , , ,
p,p,p,p,p,p,p,p
r,n,b,q,k,b,n,r

R,N,B,Q,K,B,N,R
P,P,P,P,P,P,P,P
 , , , , , , ,
 , , , , , , ,
 , , , ,p, , ,
 , , , , , , ,
p,p,p,p, ,p,p,p
r,n,b,q,k,b,n,r

Accessing array elements

Array elements are nothing less than object properties, so they are accessed as such.

var myArray = new Array("Wind", "Rain", "Fire");
myArray[0]; // "Wind"
myArray[1]; // "Rain"
// etc.
myArray.length; // 3

// Even if indices are properties, the following notation throws a syntax error
myArray.2;

// It should be noted that in JavaScript, object property names are strings. Consequently,
myArray[0] === myArray["0"];
myArray[1] === myArray["1"];
// etc.

// However, this should be considered carefully
myArray[02]; // "Fire". The number 02 is converted as the "2" string
myArray["02"]; // undefined. There is no property named "02"

Relationship between length and numerical properties

An array's length property and numerical properties are connected. Here is some code explaining how this relationship works.

var a = [];

a[0] = 'a';
console.log(a[0]); // 'a'
console.log(a.length); // 1

a[1] = 32;
console.log(a[1]); // 32
console.log(a.length); // 2

a[13] = 12345;
console.log(a[13]); // 12345
console.log(a.length); // 14

a.length = 10;
console.log(a[13]); // undefined, when reducing the length elements after length+1 are removed
console.log(a.length); // 10

Creating an array using the result of a match

The result of a match between a regular expression and a string can create an array. This array has properties and elements that provide information about the match. An array is the return value of RegExp.exec, String.match, and String.replace. To help explain these properties and elements, look at the following example and then refer to the table below:

// Match one d followed by one or more b's followed by one d
// Remember matched b's and the following d
// Ignore case

var myRe = /d(b+)(d)/i;
var myArray = myRe.exec("cdbBdbsbz");

The properties and elements returned from this match are as follows:

Property/Element Description Example
input A read-only property that reflects the original string against which the cdbBdbsbz
regular expression was matched.
index A read-only property that is the zero-based index of the match in the string. 1
[0] A read-only element that specifies the last matched characters. dbBd
[1], ...[n] Read-only elements that specify the parenthesized substring matches, if included in [1]: bB [2]: d
the regular expression. The number of possible parenthesized substrings is unlimited.
Documentation for this class comes from [MDN](https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array) and is available under [Creative Commons: Attribution-Sharealike license](http://creativecommons.org/licenses/by-sa/2.0/).
No members found using the current filters

properties

Instance Properties

length : Number

Reflects the number of elements in an array.

The value of the length property is an integer with a positive sign and a value less than 2 to the 32 power (232).

You can set the length property to truncate an array at any time. When you extend an array by changing its length property, the number of actual elements does not increase; for example, if you set length to 3 when it is currently 2, the array still contains only 2 elements.

In the following example the array numbers is iterated through by looking at the length property to see how many elements it has. Each value is then doubled.

var numbers = [1,2,3,4,5];
for (var i = 0; i < numbers.length; i++) {
    numbers[i] *= 2;
}
// numbers is now [2,4,6,8,10];

The following example shortens the array statesUS to a length of 50 if the current length is greater than 50.

if (statesUS.length > 50) {
    statesUS.length=50
}

methods

Instance Methods

concat ( values ) : Array

Returns a new array comprised of this array joined with other array(s) and/or value(s).

concat creates a new array consisting of the elements in the this object on which it is called, followed in order by, for each argument, the elements of that argument (if the argument is an array) or the argument itself (if the argument is not an array).

concat does not alter this or any of the arrays provided as arguments but instead returns a "one level deep" copy that contains copies of the same elements combined from the original arrays. Elements of the original arrays are copied into the new array as follows: Object references (and not the actual object): concat copies object references into the new array. Both the original and new array refer to the same object. That is, if a referenced object is modified, the changes are visible to both the new and original arrays. Strings and numbers (not String and Number objects): concat copies the values of strings and numbers into the new array.

Any operation on the new array will have no effect on the original arrays, and vice versa.

Concatenating two arrays

The following code concatenates two arrays:

var alpha = ["a", "b", "c"];
var numeric = [1, 2, 3];

// creates array ["a", "b", "c", 1, 2, 3]; alpha and numeric are unchanged
var alphaNumeric = alpha.concat(numeric);

Concatenating three arrays

The following code concatenates three arrays:

var num1 = [1, 2, 3];
var num2 = [4, 5, 6];
var num3 = [7, 8, 9];

// creates array [1, 2, 3, 4, 5, 6, 7, 8, 9]; num1, num2, num3 are unchanged
var nums = num1.concat(num2, num3);

Concatenating values to an array

The following code concatenates three values to an array:

var alpha = ['a', 'b', 'c'];

// creates array ["a", "b", "c", 1, 2, 3], leaving alpha unchanged
var alphaNumeric = alpha.concat(1, [2, 3]);

Parameters

values :  Object...

Arrays and/or values to concatenate to the resulting array.

Returns

:Array
New array.

constructor ( [items] )

Creates new Array object.

Parameters

items :  Number/Object... (optional)

Either a number that specifies the length of array or any number of items for the array.

every ( callback, [thisObject] ) : Boolean

Tests whether all elements in the array pass the test implemented by the provided function.

every executes the provided callback function once for each element present in the array until it finds one where callback returns a false value. If such an element is found, the every method immediately returns false. Otherwise, if callback returned a true value for all elements, every will return true. callback is invoked only for indexes of the array which have assigned values; it is not invoked for indexes which have been deleted or which have never been assigned values.

If a thisObject parameter is provided to every, it will be used as the this for each invocation of the callback. If it is not provided, or is null, the global object associated with callback is used instead.

every does not mutate the array on which it is called.

The range of elements processed by every is set before the first invocation of callback. Elements which are appended to the array after the call to every begins will not be visited by callback. If existing elements of the array are changed, their value as passed to callback will be the value at the time every visits them; elements that are deleted are not visited.

every acts like the "for all" quantifier in mathematics. In particular, for an empty array, it returns true. (It is vacuously true that all elements of the empty set satisfy any given condition.)

The following example tests whether all elements in the array are bigger than 10.

function isBigEnough(element, index, array) {
  return (element >= 10);
}
var passed = [12, 5, 8, 130, 44].every(isBigEnough);
// passed is false
passed = [12, 54, 18, 130, 44].every(isBigEnough);
// passed is true

NOTE: This method is part of the ECMAScript 5 standard.

Parameters

callback :  Function

Function to test for each element.

value :  Mixed

The element value.

index :  Number

The element index.

array :  Array

The array being traversed.

return :  Boolean

Should return true when element passes the test.

thisObject :  Object (optional)

Object to use as `this` when executing `callback`.

Returns

:Boolean
True when all elements pass the test.

filter ( callback, [thisObject] ) : Array

Creates a new array with all elements that pass the test implemented by the provided function.

filter calls a provided callback function once for each element in an array, and constructs a new array of all the values for which callback returns a true value. callback is invoked only for indexes of the array which have assigned values; it is not invoked for indexes which have been deleted or which have never been assigned values. Array elements which do not pass the callback test are simply skipped, and are not included in the new array.

If a thisObject parameter is provided to filter, it will be used as the this for each invocation of the callback. If it is not provided, or is null, the global object associated with callback is used instead.

filter does not mutate the array on which it is called.

The range of elements processed by filter is set before the first invocation of callback. Elements which are appended to the array after the call to filter begins will not be visited by callback. If existing elements of the array are changed, or deleted, their value as passed to callback will be the value at the time filter visits them; elements that are deleted are not visited.

The following example uses filter to create a filtered array that has all elements with values less than 10 removed.

function isBigEnough(element, index, array) {
  return (element >= 10);
}
var filtered = [12, 5, 8, 130, 44].filter(isBigEnough);
// filtered is [12, 130, 44]

NOTE: This method is part of the ECMAScript 5 standard.

Parameters

callback :  Function

Function to test for each element.

value :  Mixed

The element value.

index :  Number

The element index.

array :  Array

The array being traversed.

return :  Boolean

Should return true when element passes the test.

thisObject :  Object (optional)

Object to use as `this` when executing `callback`.

Returns

:Array
Array of elements that passed the test.

forEach ( callback, [thisArg] )

Executes a provided function once per array element.

forEach executes the provided function (callback) once for each element present in the array. callback is invoked only for indexes of the array which have assigned values; it is not invoked for indexes which have been deleted or which have never been assigned values.

If a thisArg parameter is provided to forEach, it will be used as the this value for each callback invocation as if callback.call(thisArg, element, index, array) was called. If thisArg is undefined or null, the this value within the function depends on whether the function is in strict mode or not (passed value if in strict mode, global object if in non-strict mode).

The range of elements processed by forEach is set before the first invocation of callback. Elements which are appended to the array after the call to forEach begins will not be visited by callback. If existing elements of the array are changed, or deleted, their value as passed to callback will be the value at the time forEach visits them; elements that are deleted are not visited.

The following code logs a line for each element in an array:

function logArrayElements(element, index, array) {
    console.log("a[" + index + "] = " + element);
}
[2, 5, 9].forEach(logArrayElements);
// logs:
// a[0] = 2
// a[1] = 5
// a[2] = 9

NOTE: This method is part of the ECMAScript 5 standard.

Parameters

callback :  Function

Function to execute for each element.

value :  Mixed

The element value.

index :  Number

The element index.

array :  Array

The array being traversed.

thisArg :  Object (optional)

Object to use as `this` when executing `callback`.

indexOf ( searchElement, [fromIndex] ) : Number

Returns the first index at which a given element can be found in the array, or -1 if it is not present.

indexOf compares searchElement to elements of the Array using strict equality (the same method used by the ===, or triple-equals, operator).

var array = [2, 5, 9];
var index = array.indexOf(2);
// index is 0
index = array.indexOf(7);
// index is -1

NOTE: This method is part of the ECMAScript 5 standard.

Parameters

searchElement :  Mixed

Element to locate in the array.

fromIndex :  Number (optional)

The index at which to begin the search. Defaults to 0, i.e. the whole array will be searched. If the index is greater than or equal to the length of the array, -1 is returned, i.e. the array will not be searched. If negative, it is taken as the offset from the end of the array. Note that even when the index is negative, the array is still searched from front to back. If the calculated index is less than 0, the whole array will be searched.

Returns

:Number
The index of element found or -1.

join ( separator ) : String

Joins all elements of an array into a string.

The string conversions of all array elements are joined into one string.

The following example creates an array, a, with three elements, then joins the array three times: using the default separator, then a comma and a space, and then a plus.

var a = new Array("Wind","Rain","Fire");
var myVar1 = a.join();      // assigns "Wind,Rain,Fire" to myVar1
var myVar2 = a.join(", ");  // assigns "Wind, Rain, Fire" to myVar2
var myVar3 = a.join(" + "); // assigns "Wind + Rain + Fire" to myVar3

Parameters

separator :  String

Specifies a string to separate each element of the array. The separator is converted to a string if necessary. If omitted, the array elements are separated with a comma.

Returns

:String
A string of the array elements.

lastIndexOf ( searchElement, [fromIndex] ) : Number

Returns the last index at which a given element can be found in the array, or -1 if it is not present. The array is searched backwards, starting at fromIndex.

lastIndexOf compares searchElement to elements of the Array using strict equality (the same method used by the ===, or triple-equals, operator).

var array = [2, 5, 9, 2];
var index = array.lastIndexOf(2);
// index is 3
index = array.lastIndexOf(7);
// index is -1
index = array.lastIndexOf(2, 3);
// index is 3
index = array.lastIndexOf(2, 2);
// index is 0
index = array.lastIndexOf(2, -2);
// index is 0
index = array.lastIndexOf(2, -1);
// index is 3

NOTE: This method is part of the ECMAScript 5 standard.

Parameters

searchElement :  Mixed

Element to locate in the array.

fromIndex :  Number (optional)

The index at which to start searching backwards. Defaults to the array's length, i.e. the whole array will be searched. If the index is greater than or equal to the length of the array, the whole array will be searched. If negative, it is taken as the offset from the end of the array. Note that even when the index is negative, the array is still searched from back to front. If the calculated index is less than 0, -1 is returned, i.e. the array will not be searched.

Returns

:Number
The index of element found or -1.

map ( callback, [thisObject] ) : Array

Creates a new array with the results of calling a provided function on every element in this array.

map calls a provided callback function once for each element in an array, in order, and constructs a new array from the results. callback is invoked only for indexes of the array which have assigned values; it is not invoked for indexes which have been deleted or which have never been assigned values.

If a thisArg parameter is provided to map, it will be used as the this for each invocation of the callback. If it is not provided, or is null, the global object associated with callback is used instead.

map does not mutate the array on which it is called.

The range of elements processed by map is set before the first invocation of callback. Elements which are appended to the array after the call to map begins will not be visited by callback. If existing elements of the array are changed, or deleted, their value as passed to callback will be the value at the time map visits them; elements that are deleted are not visited.

The following code creates an array of "plural" forms of nouns from an array of their singular forms.

function fuzzyPlural(single) {
  var result = single.replace(/o/g, 'e');
  if( single === 'kangaroo'){
    result += 'se';
  }
  return result;
}

var words = ["foot", "goose", "moose", "kangaroo"];
console.log(words.map(fuzzyPlural));

// ["feet", "geese", "meese", "kangareese"]

The following code takes an array of numbers and creates a new array containing the square roots of the numbers in the first array.

var numbers = [1, 4, 9];
var roots = numbers.map(Math.sqrt);
// roots is now [1, 2, 3], numbers is still [1, 4, 9]

NOTE: This method is part of the ECMAScript 5 standard.

Parameters

callback :  Function

Function that produces an element of the new Array from an element of the current one.

value :  Mixed

The element value.

index :  Number

The element index.

array :  Array

The array being traversed.

return :  Boolean

Should return true when element passes the test.

thisObject :  Object (optional)

Object to use as `this` when executing `callback`.

Returns

:Array
Array of the return values of `callback` function.

pop Object

The pop method removes the last element from an array and returns that value to the caller.

pop is intentionally generic; this method can be called or applied to objects resembling arrays. Objects which do not contain a length property reflecting the last in a series of consecutive, zero-based numerical properties may not behave in any meaningful manner.

var myFish = ["angel", "clown", "mandarin", "surgeon"];
var popped = myFish.pop();
alert(popped); // Alerts 'surgeon'

Returns

:Object
The last element in the array

push ( elements ) : Number

Adds one or more elements to the end of an array and returns the new length of the array.

push is intentionally generic. This method can be called or applied to objects resembling arrays. The push method relies on a length property to determine where to start inserting the given values. If the length property cannot be converted into a number, the index used is 0. This includes the possibility of length being nonexistent, in which case length will also be created.

The only native, array-like objects are strings, although they are not suitable in applications of this method, as strings are immutable.

Adding elements to an array

The following code creates the sports array containing two elements, then appends two elements to it. After the code executes, sports contains 4 elements: "soccer", "baseball", "football" and "swimming".

var sports = ["soccer", "baseball"];
sports.push("football", "swimming");

Parameters

elements :  Object...

The elements to add to the end of the array.

Returns

:Number
The new length property of the object upon which the method was called.

reduce ( callback, [initialValue] ) : Mixed

Applies a function against an accumulator and each value of the array (from left-to-right) as to reduce it to a single value.

reduce executes the callback function once for each element present in the array, excluding holes in the array.

The first time the callback is called, previousValue and currentValue can be one of two values. If initialValue is provided in the call to reduce, then previousValue will be equal to initialValue and currentValue will be equal to the first value in the array. If no initialValue was provided, then previousValue will be equal to the first value in the array and currentValue will be equal to the second.

Suppose the following use of reduce occurred:

[0,1,2,3,4].reduce(function(previousValue, currentValue, index, array){
  return previousValue + currentValue;
});

The callback would be invoked four times, with the arguments and return values in each call being as follows:

previousValue currentValue index array return value
first call 0 1 1 [0,1,2,3,4] 1
second call 1 2 2 [0,1,2,3,4] 3
third call 3 3 3 [0,1,2,3,4] 6
fourth call 6 4 4 [0,1,2,3,4] 10

The value returned by reduce would be that of the last callback invocation (10).

If you were to provide an initial value as the second argument to reduce, the result would look like this:

[0,1,2,3,4].reduce(function(previousValue, currentValue, index, array){
  return previousValue + currentValue;
}, 10);
previousValue currentValue index array return value
first call 10 0 0 [0,1,2,3,4] 10
second call 10 1 1 [0,1,2,3,4] 11
third call 11 2 2 [0,1,2,3,4] 13
fourth call 13 3 3 [0,1,2,3,4] 16
fifth call 16 4 4 [0,1,2,3,4] 20

The value returned by reduce this time would be, of course, 20.

Example: Sum up all values within an array:

var total = [0, 1, 2, 3].reduce(function(a, b) {
    return a + b;
});
// total == 6

Example: Flatten an array of arrays:

var flattened = [[0, 1], [2, 3], [4, 5]].reduce(function(a, b) {
    return a.concat(b);
});
// flattened is [0, 1, 2, 3, 4, 5]

NOTE: This method is part of the ECMAScript 5 standard.

Parameters

callback :  Function

Function to execute on each value in the array.

previousValue :  Mixed

The value previously returned in the last invocation of the callback, or initialValue, if supplied.

currentValue :  Mixed

The current element being processed in the array.

index :  Number

The index of the current element being processed in the array.

array :  Array

The array reduce was called upon.

initialValue :  Mixed (optional)

Object to use as the first argument to the first call of the `callback`.

Returns

:Mixed
The value returned by final invocation of the `callback`.

reduceRight ( callback, [initialValue] ) : Mixed

Applies a function simultaneously against two values of the array (from right-to-left) as to reduce it to a single value.

reduceRight executes the callback function once for each element present in the array, excluding holes in the array.

The first time the callback is called, previousValue and currentValue can be one of two values. If initialValue is provided in the call to reduceRight, then previousValue will be equal to initialValue and currentValue will be equal to the last value in the array. If no initialValue was provided, then previousValue will be equal to the last value in the array and currentValue will be equal to the second-to-last value.

Some example run-throughs of the function would look like this:

[0, 1, 2, 3, 4].reduceRight(function(previousValue, currentValue, index, array) {
    return previousValue + currentValue;
});

// First call
previousValue = 4, currentValue = 3, index = 3

// Second call
previousValue = 7, currentValue = 2, index = 2

// Third call
previousValue = 9, currentValue = 1, index = 1

// Fourth call
previousValue = 10, currentValue = 0, index = 0

// array is always the object [0,1,2,3,4] upon which reduceRight was called

// Return Value: 10

And if you were to provide an initialValue, the result would look like this:

[0, 1, 2, 3, 4].reduceRight(function(previousValue, currentValue, index, array) {
    return previousValue + currentValue;
}, 10);

// First call
previousValue = 10, currentValue = 4, index = 4

// Second call
previousValue = 14, currentValue = 3, index = 3

// Third call
previousValue = 17, currentValue = 2, index = 2

// Fourth call
previousValue = 19, currentValue = 1, index = 1

// Fifth call
previousValue = 20, currentValue = 0, index = 0

// array is always the object [0,1,2,3,4] upon which reduceRight was called

// Return Value: 20

NOTE: This method is part of the ECMAScript 5 standard.

Parameters

callback :  Function

Function to execute on each value in the array.

previousValue :  Mixed

The value previously returned in the last invocation of the callback, or initialValue, if supplied.

currentValue :  Mixed

The current element being processed in the array.

index :  Number

The index of the current element being processed in the array.

array :  Array

The array reduceRight was called upon.

initialValue :  Mixed (optional)

Object to use as the first argument to the first call of the `callback`.

Returns

:Mixed
The value returned by final invocation of the `callback`.

reverse Array

Reverses the order of the elements of an array -- the first becomes the last, and the last becomes the first.

The reverse method transposes the elements of the calling array object in place, mutating the array, and returning a reference to the array.

The following example creates an array myArray, containing three elements, then reverses the array.

var myArray = ["one", "two", "three"];
myArray.reverse();

This code changes myArray so that:

  • myArray[0] is "three"
  • myArray[1] is "two"
  • myArray[2] is "one"

Returns

:Array
A reference to the array

shift Object

Removes the first element from an array and returns that element.

The shift method removes the element at the zeroeth index and shifts the values at consecutive indexes down, then returns the removed value.

shift is intentionally generic; this method can be called or applied to objects resembling arrays. Objects which do not contain a length property reflecting the last in a series of consecutive, zero-based numerical properties may not behave in any meaningful manner.

The following code displays the myFish array before and after removing its first element. It also displays the removed element:

// assumes a println function is defined
var myFish = ["angel", "clown", "mandarin", "surgeon"];
println("myFish before: " + myFish);
var shifted = myFish.shift();
println("myFish after: " + myFish);
println("Removed this element: " + shifted);

This example displays the following:

myFish before: angel,clown,mandarin,surgeon
myFish after: clown,mandarin,surgeon
Removed this element: angel

Returns

:Object
The first element of the array prior to shifting.

slice ( begin, end ) : Array

Extracts a section of an array and returns a new array.

slice does not alter the original array, but returns a new "one level deep" copy that contains copies of the elements sliced from the original array. Elements of the original array are copied into the new array as follows:

  • For object references (and not the actual object), slice copies object references into the new array. Both the original and new array refer to the same object. If a referenced object changes, the changes are visible to both the new and original arrays.
  • For strings and numbers (not String and Number objects), slice copies strings and numbers into the new array. Changes to the string or number in one array does not affect the other array.

If a new element is added to either array, the other array is not affected.

Using slice

In the following example, slice creates a new array, newCar, from myCar. Both include a reference to the object myHonda. When the color of myHonda is changed to purple, both arrays reflect the change.

// Using slice, create newCar from myCar.
var myHonda = { color: "red", wheels: 4, engine: { cylinders: 4, size: 2.2 } };
var myCar = [myHonda, 2, "cherry condition", "purchased 1997"];
var newCar = myCar.slice(0, 2);

// Print the values of myCar, newCar, and the color of myHonda
//  referenced from both arrays.
print("myCar = " + myCar.toSource());
print("newCar = " + newCar.toSource());
print("myCar[0].color = " + myCar[0].color);
print("newCar[0].color = " + newCar[0].color);

// Change the color of myHonda.
myHonda.color = "purple";
print("The new color of my Honda is " + myHonda.color);

// Print the color of myHonda referenced from both arrays.
print("myCar[0].color = " + myCar[0].color);
print("newCar[0].color = " + newCar[0].color);

This script writes:

myCar = [{color:"red", wheels:4, engine:{cylinders:4, size:2.2}}, 2, "cherry condition",
"purchased 1997"]
newCar = [{color:"red", wheels:4, engine:{cylinders:4, size:2.2}}, 2]
myCar[0].color = red
newCar[0].color = red
The new color of my Honda is purple
myCar[0].color = purple
newCar[0].color = purple

Parameters

begin :  Number

Zero-based index at which to begin extraction. As a negative index, `start` indicates an offset from the end of the sequence. `slice(-2)` extracts the second-to-last element and the last element in the sequence

end :  Number

Zero-based index at which to end extraction. slice extracts up to but not including `end`. `slice(1,4)` extracts the second element through the fourth element (elements indexed 1, 2, and 3). As a negative index, end indicates an offset from the end of the sequence. `slice(2,-1)` extracts the third element through the second-to-last element in the sequence. If `end` is omitted, slice extracts to the end of the sequence.

Returns

:Array
Array from the new start position up to (but not including) the specified end position.

some ( callback, [thisObject] ) : Boolean

Tests whether some element in the array passes the test implemented by the provided function.

some executes the callback function once for each element present in the array until it finds one where callback returns a true value. If such an element is found, some immediately returns true. Otherwise, some returns false. callback is invoked only for indexes of the array which have assigned values; it is not invoked for indexes which have been deleted or which have never been assigned values.

If a thisObject parameter is provided to some, it will be used as the this for each invocation of the callback. If it is not provided, or is null, the global object associated with callback is used instead.

some does not mutate the array on which it is called.

The range of elements processed by some is set before the first invocation of callback. Elements that are appended to the array after the call to some begins will not be visited by callback. If an existing, unvisited element of the array is changed by callback, its value passed to the visiting callback will be the value at the time that some visits that element's index; elements that are deleted are not visited.

The following example tests whether some element in the array is bigger than 10.

function isBigEnough(element, index, array) {
  return (element >= 10);
}
var passed = [2, 5, 8, 1, 4].some(isBigEnough);
// passed is false
passed = [12, 5, 8, 1, 4].some(isBigEnough);
// passed is true

NOTE: This method is part of the ECMAScript 5 standard.

Parameters

callback :  Function

Function to test for each element.

value :  Mixed

The element value.

index :  Number

The element index.

array :  Array

The array being traversed.

return :  Boolean

Should return true when element passes the test.

thisObject :  Object (optional)

Object to use as `this` when executing `callback`.

Returns

:Boolean
True when at least one element passes the test.

sort ( compareFunction ) : Array

Sorts the elements of an array.

If compareFunction is not supplied, elements are sorted by converting them to strings and comparing strings in lexicographic ("dictionary" or "telephone book," not numerical) order. For example, "80" comes before "9" in lexicographic order, but in a numeric sort 9 comes before 80.

If compareFunction is supplied, the array elements are sorted according to the return value of the compare function. If a and b are two elements being compared, then: If compareFunction(a, b) is less than 0, sort a to a lower index than b. If compareFunction(a, b) returns 0, leave a and b unchanged with respect to each other, but sorted with respect to all different elements. Note: the ECMAscript standard does not guarantee this behaviour, and thus not all browsers respect this. If compareFunction(a, b) is greater than 0, sort b to a lower index than a. compareFunction(a, b) must always returns the same value when given a specific pair of elements a and b as its two arguments. If inconsistent results are returned then the sort order is undefined

So, the compare function has the following form:

function compare(a, b)
{
    if (a is less than b by some ordering criterion)
        return -1;
    if (a is greater than b by the ordering criterion)
       return 1;
    // a must be equal to b
    return 0;
}

To compare numbers instead of strings, the compare function can simply subtract b from a:

function compareNumbers(a, b)
{
return a - b;
}

The sort() method can be conveniently used with closures:

var numbers = [4, 2, 5, 1, 3];
numbers.sort(function(a, b) {
    return a - b;
});
print(numbers);

Parameters

compareFunction :  Function

Specifies a function that defines the sort order. If omitted, the array is sorted lexicographically (in dictionary order) according to the string conversion of each element.

Returns

:Array
A reference to the array

splice ( index, howMany, elements ) : Array

Adds and/or removes elements from an array.

If you specify a different number of elements to insert than the number you're removing, the array will have a different length at the end of the call.

// assumes a print function is defined
var myFish = ["angel", "clown", "mandarin", "surgeon"];
print("myFish: " + myFish);

var removed = myFish.splice(2, 0, "drum");
print("After adding 1: " + myFish);
print("removed is: " + removed);

removed = myFish.splice(3, 1);
print("After removing 1: " + myFish);
print("removed is: " + removed);

removed = myFish.splice(2, 1, "trumpet");
print("After replacing 1: " + myFish);
print("removed is: " + removed);

removed = myFish.splice(0, 2, "parrot", "anemone", "blue");
print("After replacing 2: " + myFish);
print("removed is: " + removed);

This script displays:

myFish: angel,clown,mandarin,surgeon
After adding 1: angel,clown,drum,mandarin,surgeon
removed is:
After removing 1: angel,clown,drum,surgeon
removed is: mandarin
After replacing 1: angel,clown,trumpet,surgeon
removed is: drum
After replacing 2: parrot,anemone,blue,trumpet,surgeon
removed is: angel,clown

Parameters

index :  Number

Index at which to start changing the array. If negative, will begin that many elements from the end.

howMany :  Number

An integer indicating the number of old array elements to remove. If `howMany` is 0, no elements are removed. In this case, you should specify at least one new element. If no `howMany` parameter is specified all elements after index are removed.

elements :  Object...

The elements to add to the array. If you don't specify any elements, splice simply removes elements from the array.

Returns

:Array
An array containing the removed elements. If only one element is removed, an array of one element is returned..

toString String

Returns a string representing the array and its elements. Overrides the Object.prototype.toString method.

The Array object overrides the toString method of Object. For Array objects, the toString method joins the array and returns one string containing each array element separated by commas. For example, the following code creates an array and uses toString to convert the array to a string.

var monthNames = new Array("Jan","Feb","Mar","Apr");
myVar = monthNames.toString(); // assigns "Jan,Feb,Mar,Apr" to myVar

JavaScript calls the toString method automatically when an array is to be represented as a text value or when an array is referred to in a string concatenation.

Returns

:String
The array as a string.

unshift ( elements ) : Number

Adds one or more elements to the front of an array and returns the new length of the array.

The unshift method inserts the given values to the beginning of an array-like object.

unshift is intentionally generic; this method can be called or applied to objects resembling arrays. Objects which do not contain a length property reflecting the last in a series of consecutive, zero-based numerical properties may not behave in any meaningful manner.

The following code displays the myFish array before and after adding elements to it.

// assumes a println function exists
myFish = ["angel", "clown"];
println("myFish before: " + myFish);
unshifted = myFish.unshift("drum", "lion");
println("myFish after: " + myFish);
println("New length: " + unshifted);

This example displays the following:

myFish before: ["angel", "clown"]
myFish after: ["drum", "lion", "angel", "clown"]
New length: 4

Parameters

elements :  Object...

The elements to add to the front of the array.

Returns

:Number
The array's new length.
Static Methods

isArray ( obj ) : Boolean
static sta

Returns true if an object is an array, false if it is not.

// all following calls return true
Array.isArray([]);
Array.isArray([1]);
Array.isArray( new Array() );
Array.isArray( Array.prototype ); // Little known fact: Array.prototype itself is an array.

// all following calls return false
Array.isArray();
Array.isArray({});
Array.isArray(null);
Array.isArray(undefined);
Array.isArray(17);
Array.isArray("Array");
Array.isArray(true);
Array.isArray(false);
Array.isArray({ __proto__ : Array.prototype });

NOTE: This method is part of the ECMAScript 5 standard.

Parameters

obj :  Mixed

The object to be checked.

Returns

:Boolean
True when Array.

Ext JS 6.5.0 - Modern Toolkit