Includes() vs indexOf() in JavaScript

John Samuel Obinna on September 04, 2017

ES2016 Specifications included the includes() method for Array data structure. The includes() method check if an array includes a certain ... [Read Full]
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Nice article.
I have one correction for you.

The line:
if(array.indexOf(4) >= -1 )

Needs to be:
if(array.indexOf(4) > -1 )

In order to check, whether an element is in the array. Otherwise the condition would always be true.


Yeah. indexOf() always return -1 if element is not found. Thanks Jonas


You forgot to mention one of the main differences between includes() and indexOf().

IE does not support includes() whereas it supports the other.


I think IE11 started supporting Array.prototype.includes. Exact version that I'm using is 11.904.16299.0


Uhm in all honesty isn't +0 exactly the same as -0? So is there any real life need to distinguish between +0 and -0?

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