Array.prototype.includes() does not return the index, but boolean

[mestaritonttu]

.includes should not be under "Search for a specified value within an array and return its index (or -1 if not found)."

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/includes

The includes() method determines whether an array includes a certain value among its entries, returning true or false as appropriate.

[mestaritonttu]

@camsong this is not fixed yet, please reopen.

[vlakoff]

Refs the relevant section: https://github.com/camsong/You-Dont-Need-jQuery#6.1

A confusion seems to have been introduced at some point, because $.inArray() doesn't return a boolean (item found or not), but the index of the item, exactly as Array.prototype.indexOf() does. (Indeed, that jQuery function has been badly named.)

Therefore, the correct snippets are:

• Search for a specified value within an array and return its index (or -1 if not found):

// jQuery
$.inArray(item, array);

// Native, and ES6-way
array.indexOf(item);

• Test if a specified value is found within an array:

// jQuery
$.inArray(item, array) > -1;

// Native
array.indexOf(item) > -1;

// ES6-way
array.includes(item);