ng we are dealing with
an arrayâand it just works, thanks to the way JavaScript allows us to
establish the execution context in any way we want.

js

    
    
    const obj = {
      length: 0,
    
      addElem(elem) {
        // obj.length is automatically incremented
        // every time an element is added.
        [].push.call(this, elem);
      },
    };
    
    // Let's add some empty objects just to illustrate.
    obj.addElem({});
    obj.addElem({});
    console.log(obj.length); // 2
    

Note that although ` obj ` is not an array, the method ` push ` successfully
incremented ` obj ` 's ` length ` property just like if we were dealing with
an actual array.

##  Specifications

Specification  
---  
[ ECMAScript Language Specification  
#  sec-array.prototype.push  ](https://tc39.es/ecma262/multipage/indexed-
collections.html#sec-array.prototype.push)  
  
##  Browser compatibility

BCD tables only load in the browser  with JavaScript enabled. Enable
JavaScript to view data.

##  See also

  * [ Polyfill of ` Array.prototype.push ` in ` core-js ` with fixes of this method ](https://github.com/zloirock/core-js#ecmascript-array)
  * [ Indexed collections ](/en-US/docs/Web/JavaScript/Guide/Indexed_collections) guide 
  * [ ` Array ` ](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)
  * [ ` Array.prototype.pop() ` ](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/pop)
  * [ ` Array.prototype.shift() ` ](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/shift)
  * [ ` Array.prototype.unshift() ` ](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/unshift)
  * [ ` Array.prototype.concat() ` ](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/concat)
  * [ ` Array.prototype.splice() ` ](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/splice)

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