Check if object is a jQuery object

Question

Is there a fast way of checking if an object is a jQuery object or a native JavaScript object   example   var o       var e       element     function doStuff o        if  o selector            console log  object is jQuery             doStuff o   doStuff e     obviously  the code above works but it s not safe  You could potentially add a selector key to the o object and get the same result  Is there a better way of making sure that the object actually is a jQuery object   Something in line with  typeof obj     jquery

User · Answer

You can check if the object is produced by JQuery with the jquery property:

myObject.jquery // 3.3.1

=> return the number of the JQuery version if the object produced by JQuery. => otherwise, it returns undefined

User · Answer

You may also use the  jquery property as described here  http   api jquery com jquery-2   var a     what   A regular JS object     b      body     if   a jquery        falsy  since it s undefined     alert   a is a jQuery object             if   b jquery        truthy  since it s a string     alert   b is a jQuery object

User · Answer

However  There is one more way to check the object in jQuery   jQuery type a     this returns type of variable    I have made example to understand things  jsfiddle link

User · Answer

Check out the instanceof operator   var isJqueryObject   obj instanceof jQuery

User · Answer

You can use the instanceof operator  if  obj instanceof jQuery       console log  object is jQuery       Explanation  the jQuery function  aka    is implemented as a constructor function  Constructor functions are to be called with the new prefix  When you call   foo   internally jQuery translates this to new jQuery foo 1  JavaScript proceeds to initialize this inside the constructor function to point to a new instance of jQuery  setting it s properties to those found on jQuery prototype  aka jQuery fn   Thus  you get a new object where instanceof jQuery is true   1It s actually new jQuery prototype init foo   the constructor logic has been offloaded to another constructor function called init  but the concept is the same

User · Answer

return el instanceof jQuery   el size    gt  0    el  amp  amp  el tagName

User · Answer

The best way to check the instance of an object is through instanceof operator or with the method isPrototypeOf   which inspects if the prototype of an object is in another object s prototype chain    obj instanceof jQuery  jQuery prototype isPrototypeOf obj     But sometimes it might fail in the case of multiple jQuery instances on a document  As  Georgiy Ivankin mentioned      if I have   in my current namespace pointing to jQuery2 and I have an object from outer namespace  where   is jQuery1  then I have no way to use instanceof for checking if that object is a jQuery object   One way to overcome that problem is by aliasing the jQuery object in a closure or IIFE    aliases jQuery as    function    undefined              your code         console log obj instanceof         console log   prototype isPrototypeOf obj               your code      jQuery1      imports jQuery1   Other way to overcome that problem is by inquiring the jquery property in obj   jquery  in obj   However  if you try to perform that checking with primitive values  it will throw an error  so you can modify the previous checking by ensuring obj to be an Object   jquery  in Object obj    Although the previous way is not the safest  you can create the  jquery  property in an object   we can improve the validation by working with both approaches   if  obj instanceof jQuery     jquery  in Object obj         The problem here is that any object can define a property jquery as own  so a better approach would be to ask in the prototype  and ensure that the object is not null or undefined   if  obj  amp  amp   obj instanceof jQuery    obj constructor prototype jquery          Due to coercion  the if statement will make short circuit by evaluating the  amp  amp  operator when obj is any of the falsy values  null  undefined  false  0       and then proceeds to perform the other validations   Finally we can write an utility function   function isjQuery obj      return  obj  amp  amp   obj instanceof jQuery    obj constructor prototype jquery          Let s take a look at  Logical Operators and truthy   falsy

User · Answer

For those who want to know if an object is a jQuery object without having jQuery installed  the following snippet should do the work    function isJQuery obj         Each jquery object has a  jquery  attribute that contains the version of the lib    return typeof obj      object   amp  amp  obj  amp  amp  obj  jquery

User · Answer

var elArray       var elObjeto        elArray constructor    Array   TRUE elArray constructor    Object  TALSE  elObjeto constructor    Array  FALSE elObjeto constructor    Object  TRUE

[javascript] Check if object is a jQuery object

Examples related to javascript

Examples related to jquery