ayLike, 5));
    // -1
    

##  Specifications

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

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

##  See also

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

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