check if string is in array using "in"

Question

Does this not work? I thought that this was valid, but it isn't working.

var items = ["image", "text"];
console.log(this.type)
if(this.type in items){
    console.log("here")
}

console.log(this.type) displays image, but here is never displayed.

Am I doing something wrong, or am I thinking of the wrong language?

Denys Séguret · Accepted Answer · 2015-04-30 17:22:52Z

8

in checks among the property names of the object.

Here, what you need is indexOf:

if (~items.indexOf(this.type)){

Note: this is a short version for

if (items.indexOf(this.type)!==-1){

answered Apr 30, 2015 at 17:19

Denys Séguret

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Comments

Jonathan · Accepted Answer · 2015-04-30 17:22:38Z

0

You can do

var items = ["image", "text"];
var item = "image";
if (items.indexOf(item) > -1) {
  console.log("here");
}

answered Apr 30, 2015 at 17:22

Jonathan

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Alex Cassady · Accepted Answer · 2015-04-30 17:28:26Z

0

The "in" keyword in JavaScript only works for keys and properties of objects. The way I would do this:

if (items.indexOf(this.type) !== -1)

This will return the index of the type you're looking for or -1 if it's not there. If it's not equal to -1, then it's there.

answered Apr 30, 2015 at 17:28

Alex Cassady

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