Jquery entry (8): Tools

Tools

Note:JqueryCan be replaced with $

Browser
Jquery. browser (): The ID of the browser kernel. Depends on navigator. useragent.

Available value: safari opera MSIE Mozilla

Returns true in Microsoft's Internet Explorer.

Code: $. Browser. MSIE

Only prompts "this is safari!" in safari! ".

Code:

If ($. browser. Safari ){

Alert ("this is safari! ");

}

 

Jquery. browser. Version (): Browser Rendering Engine Version

Typical results:

Internet Explorer: 6.0, 7.0

Mozilla/Firefox/flock/Camino: 1.7.12, 1.8.1.3

Opera: 1, 9.20

Safari/WebKit: 312.8, 418.9

 

If ($. browser. MSIE)

Alert ($. browser. version );

 

Jquery. boxmodel (): Whether the browser uses the standard box model to render the page on the current page

Returns false in quirksmode.

Code: $. boxmodel

 

Array and object operations
Jquery. Each (OBJ, callback): Common example method, which can be used for example object and array.

Code: for example, repeat the array and use the element index and content at the same time.

$. Each ([0, 1, 2], function (I, n ){

Alert ("item #" + I + ":" + n );

});

 

Code: for example, the object is repeated, and the member name and variable content are used at the same time.

$. Each ({name: "John", Lang: "JS"}, function (I, n ){

Alert ("name:" + I + ", value:" + n );

});

 

jquery. extend (target, obj1, objn) : use one or more other objects to expand an object , returns the extended object

Code:MergeSettingsAndOptions,Modify and returnSettings.

VaR settings = {validate: false, limit: 5, name: "foo "};

VaR Options = {validate: True, name: "bar "};

Jquery. Extend (settings, options );

Result: Settings = {validate: True, limit: 5, name: "bar "}

 

Code:MergeUltsAndOptions,Do not modifyUlts.

VaR empty = {}

VaR defaults = {validate: false, limit: 5, name: "foo "};

VaR Options = {validate: True, name: "bar "};

VaR settings = jquery. Extend (empty, defaults, options );

Result:

Settings = {validate: True, limit: 5, name: "bar "}

Empty = {validate: True, limit: 5, name: "bar "}

 

Jquery. grep (array, callback, invert):Filter Array elements using filter functions

Code: filter elements smaller than 0 in the array.

$. Grep ([0, 1, 2], function (n, I ){

Return n> 0;

});

Result: [1, 2]

 

Code: exclude elements larger than 0 in the array. Use the third parameter to exclude them.

$. Grep ([0, 1, 2], function (n, I ){

Return n> 0;

}, True );

Result: [0]

 

Jquery. makearray (OBJ): Convert a class array object to an array object

<Div> first </div> <div> second </div> <div> third </div> <div> fourth </div>

Code: filter elements smaller than 0 in the array.

VaR arr = jquery. makearray (document. getelementsbytagname ("Div "));

Arr. Reverse ();//Use the array flip Function

Result:

Fourth

Third

Second

First

 

Jquery. Map (array, callback):Convert the elements in one array to another.

Code: Add 4 to each element in the original array to convert it into a new array.

$. Map ([0, 1, 2], function (n ){

Return N + 4;

});

Result: [4, 5, 6]

 

Code: Add 1 to element 0 in the original array; otherwise, delete the array.

$. Map ([0, 1, 2], function (n ){

Return n> 0? N + 1: NULL;

});

Result: [2, 3]

 

Code: each element in the original array is extended into an array containing itself and its value plus 1, and converted into a new array.

$. Map ([0, 1, 2], function (n ){

Return [N, N + 1];

});

Result: [0, 1, 1, 2, 2, 3]

 

Jquery. Unique (array):Delete repeated elements in the array

Code:Duplicate DeletionDivLabel.

$. Unique (document. getelementsbytagname ("Div "));

Result: <div>, <div> ,...

 

Test Operation
Jquery. isfunction (OBJ): Whether the test object is a function

Code: checks whether a function is used.

Function stub (){}

VaR objs = [

Function (){},

{X: 15, Y: 20 },

Null,

Stub,

"Function"

];

Jquery. Each (objs, function (I ){

VaR isfunc = jquery. isfunction (objs [I]);

$ ("Span: eq (" + I + ")"). Text (isfunc );

});

Result: True, false, false, true, false

 

String operation
Jquery. Trim (STR):Removes spaces at the start and end of a string.

$. Trim ("Hello, how are you?"); Result:" Hello, how are you? "