Operation of an array in jquery

1.each for traversing objects and arrays

1.1 Iterating through an array

$.each (Arr,function (Index,value))

1.2 Traversing JSON

The index in the callback function is an object member, and value is a variable. such as {name:ll,age:24} Name,age is an object member, the latter is a variable

To exit each, you need to use return false in the callback function

Instance:

<script type= "Text/javascript" >
var arr=[2,1,4,7,9,14,87,78];
$ (function () {
$.each (Arr,function (index,value) {
if (index==5)
{
Return false;//exit each

}
Else
{

document.write ("arr[" +index+ "]:" +value+ ";")

};


}) ;

})

</script>

2.extend

Extends an object with one or more other objects, returning the object being extended.

$.extend (target, Object1, [objectn]) merges the following object into target, with the same object members, different variables, The variable of the following object overrides the previous object variable and assigns the merged object to the target

Example: (from Jqueryapi)

Merge defaults and options without modifying the defaults.

JQuery Code:

var empty = {};var defaults = { validate: false, limit: 5, name: "foo" };var options = { validate: true, name: "bar" };var settings = jQuery.extend(empty, defaults, options);

Results:

settings == { validate: true, limit: 5, name: "bar" }empty == { validate: true, limit: 5, name: "bar" }

)

3.grep

Used to filter the array, returning the array object according to the conditions given in the callback function

$.grep (Arr,function (value,index) {},boolean)

The Boolean default is False, which causes the function to return a new array that meets the criteria, and if ture, the opposite

4.inArray

Used to find the element in the array, similar to the string in JS search (str.search) search (RE) also return index, if not found also return-1

$.inarray (Value,array)

5.isArray (arr) returns a Boolean value that determines whether an object is not an array

6map

$.map (arr,function (value) {})

An array object passes the condition in the callback function to get a new array and returns the array similar to grep, and if the values of each array are arrays, the merge of the arrays will be produced

For example

JQuery Code:

$.map( [0,1,2], function(n){  return [ n, n + 1 ];});

Results:

[0, 1, 1, 2, 2, 3]

7.merge

Used to merge two of arrays

$.merge (ARR1,ARR2);

The function returns a new array (allowing duplicate array elements to exist)

8.unique (arr)

Can be used for DOM objects, or for arrays (references)

var Yeararray = new Array( in - );
$. Unique(Yeararray); return to the var Yeararray = new Array( in - );
Yeararray. sort();
$. Unique(Yeararray); Back to 

9.parseJSON (problematic)

Resolves a JSON string to an object

$.parsejson (' {' OBJECT ': VALUE} ')

{"name":"John"} name一定是双引号

10, ToArray

Restores all DOM elements in the jquery collection to an array.

$ ("tag"). ToArray ();

Operation of an array in jquery