Jquery provides serveral utilities in the formate of $(name space). These methods are helpful to complete the programming tasks.a few of the utility methods are as show below.
$.trim()
$.trim() is used to Removes leading and trailing whitespace
$.trim( " lots of extra whitespace " );
$.each()
$.each() is used to Iterates over arrays and objects
$.each(["foo","bar","baz"],function(idx, val){
console.log("element "+ idx +" is "+ val );});
$.each({ foo:"bar", baz:"bim"},function(k, v){
console.log( k +" : "+ v );});
.each() can be called on a selection to iterate over the elements contained in the selection. .each(), not $.each(), should be used for iterating over elements in a selection.
$.inArray()
$.inArray() is used to Returns a value’s index in an array, or -1 if the value is not in the array.
var myArray =[1,2,3,5];if( $.inArray(4, myArray )!==-1){
console.log("found it!");}
$.extend()
$.extend() is used to Changes the properties of the first object using the properties of subsequent objects.
var firstObject = { foo: "bar", a: "b" };
var secondObject = { foo: "baz" };
var newObject = $.extend( firstObject, secondObject );
console.log( firstObject.foo );
console.log( newObject.foo );
$.proxy()
$.proxy() is used to Returns a function that will always run in the provided scope â that is, sets the meaning of this inside the passed function to the second argument
varmyFunction=function(){
console.log(this);};var myObject ={
foo:"bar"};myFunction();// windowvar myProxyFunction = $.proxy( myFunction, myObject );myProxyFunction();
$.browser
$.browser is used to give the information about browsers
jQuery.each( jQuery.browser,function(i, val){$("<div>"+ i +" : <span>"+ val +"</span>").appendTo( document.body );});
$.contains()
$.contains() is used to returns true if the DOM element provided by the second argument is a descendant of the DOM element provided by the first argument, whether it is a direct child or nested more deeply.
$.contains( document.documentElement, document.body ); $.contains( document.body, document.documentElement );
$.data()
$.data() is used to give the information about data
<html lang = "en"><head><title>jQuery.data demo</title><script src = "https://code.jquery.com/jquery-1.10.2.js"></script></head><body><div>The values stored were <span></span> and <span></span></div><script> var div = $( "div" )[ 0 ];jQuery.data( div, "test", { first: 25, last: "tutorials" });$( "span:first" ).text( jQuery.data( div, "test" ).first ); $( "span:last" ).text( jQuery.data( div, "test" ).last ); </script></body></html></pre>An output would be as follows
The values stored were 25 and tutorials$.fn.extend()
$.fn.extend() is used to extends the jQuery prototype
<html lang = "en"><head><script src = "https://code.jquery.com/jquery-1.10.2.js"></script></head><body><label><input type = "checkbox" name = "android">Android</label><label><input type = "checkbox" name = "ios"> IOS</label><script> jQuery.fn.extend({check: function() { return this.each(function() { this.checked = true; }); }, uncheck: function() { return this.each(function() { this.checked = false; }); } });// Use the newly created .check() method $( "input[type = 'checkbox']" ).check();</script></body></html></pre>It provides the output as shown below −https://www.tutorialspoint.com/jquery/src/fn.utilities.htm
$.isWindow()
$.isWindow() is used to recognise the window
<!doctype html><html lang = "en"><head><meta charset = "utf-8"><title>jQuery.isWindow demo</title><script src = "https://code.jquery.com/jquery-1.10.2.js"></script></head><body>Is 'window' a window? <b></b><script> $( "b" ).append( "" + $.isWindow( window ) ); </script></body></html></pre>It provides the output as shown below −https://www.tutorialspoint.com/jquery/src/iswindow.htm
$.now()
It returns a number which is representing the current time
(new Date).getTime()$.isXMLDoc()
$.isXMLDoc() checks whether a file is an xml or not
jQuery.isXMLDoc( document ) jQuery.isXMLDoc( document.body )$.globalEval()
$.globalEval() is used to execute the javascript globally
functiontest(){ jQuery.globalEval("var newVar = true;")}test();$.dequeue()
$.dequeue() is used to execute the next function in the queue
<!doctype html><html lang = "en"><head><meta charset = "utf-8"><title>jQuery.dequeue demo</title><style>div { margin: 3px; width: 50px; position: absolute; height: 50px; left: 10px; top: 30px; background-color: green; border-radius: 50px; } div.red { background-color: blue; } </style><script src = "https://code.jquery.com/jquery-1.10.2.js"></script></head><body><button>Start</button><div></div><script> $( "button" ).click(function() { $( "div" ) .animate({ left: '+ = 400px' }, 2000 ) .animate({ top: '0px' }, 600 ) .queue(function() { $( this ).toggleClass( "red" ); $.dequeue( this ); }) .animate({ left:'10px', top:'30px' }, 700 ); }); </script></body></html></pre>