Test if value is in array with underscoreJS using _.some method

Question

let array = [1234, 1233, 1232];

console.log(_.some(array, 1234));

It returns false. Do you know why?

`console.log(_.some(array, function(v){ return v === 1234}));` — Pranav C Balan, Jun 14 '16 at 10:19
Ok fine thanks! Do you maybe know a simpler method to test if a value is in array with underscore? — Xavier C., Jun 14 '16 at 10:22
You could also use [`_.contains`](http://underscorejs.org/#contains) e.g `_.contains(array, 1234)` — Gruff Bunny, Jun 14 '16 at 10:49
Yes, I know why, because I read the documentation for `_.some`. — , Jun 24 '16 at 05:12

Pranav C Balan · Accepted Answer · 2016-06-24T05:16:13.360

2

As per the documentation of _.some() method, second argument should be a predicate function

console.log(_.some(array, function(v){ return v === 1234}));

In this particular case you can simply use native javascript Array#indexOf method.

console.log(array.indexOf(1234) > -1);

Also there is native JavaScript Array#some method.

console.log(array.some(function(v){ return v === 1234}));

console.log(array.some(v => v == 1234))

edited Jun 24 '16 at 05:16

answered Jun 14 '16 at 10:23

Pranav C Balan

1

There is also ES5 *some* and ECMAScript 2015 arrow functions to give: `array.some(v=>v==1234)`. ;-) – RobG Jun 14 '16 at 10:26

Krishnakant · Answer 2 · 2016-06-24T04:08:24.400

0

With UNDERSCORE.JS you can simply use,

console.log(_.indexOf(array, 1234) >= 0)

edited Jun 24 '16 at 04:08

answered Jun 14 '16 at 10:34

Krishnakant

2 Answers2