tIndexOf(undefined)); // -1
    

###  Calling lastIndexOf() on non-array objects

The ` lastIndexOf() ` method reads the ` length ` property of ` this ` and
then accesses each property whose key is a nonnegative integer less than `
length ` .

js

    
    
    const arrayLike = {
      length: 3,
      0: 2,
      1: 3,
      2: 2,
      3: 5, // ignored by lastIndexOf() since length is 3
    };
    console.log(Array.prototype.lastIndexOf.call(arrayLike, 2));
    // 2
    console.log(Array.prototype.lastIndexOf.call(arrayLike, 5));
    // -1
    

##  Specifications

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

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

##  See also

  * [ Polyfill of ` Array.prototype.lastIndexOf ` in ` core-js ` ](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.findIndex() ` ](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findIndex)
  * [ ` Array.prototype.findLastIndex() ` ](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findLastIndex)
  * [ ` Array.prototype.indexOf() ` ](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf)
  * [ ` TypedArray.prototype.lastIndexOf() ` ](/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/lastIndexOf)
  * [ ` String.prototype.lastIndexOf() ` ](/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/lastIndexOf)

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