Miscellaneous properties and functions

These utility methods do not fit neatly into the previous categories, but are often very useful when writing scripts using jQuery.

Properties of the jQuery object

Property	Description
$.support	Returns an object containing properties indicating whether the browser supports various features and standards.

Arrays and objects

Function	Description
$.each(collection, callback)	Iterates over collection, executing callback for each item.
$.extend(target, addition, ...)	Modifies the object target by adding properties from the other supplied objects.
$.grep(array, callback, [invert])	Filters array by using callback as a test.
$.makeArray(object)	Converts object into an array.
$.map(array, callback)	Constructs a new array consisting of the result of callback being called on each item.
$.inArray(value, array)	Determines whether value is in array.
$.merge(array1, array2)	Combines the contents of array1 and array2.
$.unique(array)	Removes any duplicate DOM elements from array.

Object introspection

Function	Description
$.isArray(object)	Determines whether object is a true JavaScript array.
$.isEmptyObject(object)	Determines whether object is empty.
$.isFunction(object)	Determines whether object is a function.
$.isPlainObject(object)	Determines whether object was created as an object literal or with new Object.
$.isNumeric(object)	Determines whether object is a numeric scalar value.
$.isWindow(object)	Determines whether object represents a browser window.
$.isXMLDoc(object)	Determines whether object is an XML node.
$.type(object)	Gets the JavaScript class of object.

Other

Function	Description
$.trim(string)	Removes whitespace from the ends of string.
$.noConflict([removeAll])	Reverts $ to its pre-jQuery definition.
$.noop()	A function that does nothing.
$.now()	The current time in milliseconds since the epoch.
$.holdReady(hold)	Stops the ready event from being triggered, or releases this hold.