How to check if a list contains a string in javascript?

Question

How can I test if the string "Orange" without quotes, exists in a list such as the one below, using javascript?

var suggestionList = ["Apple", "Orange", "Kiwi"];

what do you mean by without quotes? – pritesh Apr 22 '16 at 01:06 — pritesh, Apr 22 '16 at 01:06
http://www.w3schools.com/jsref/jsref_indexof_array.asp – brs Apr 22 '16 at 01:06 — brs, Apr 22 '16 at 01:06

ippi · Accepted Answer · 2018-05-25T06:02:43.517

37

indexOf() is the default to use in such cases.

if( suggestionList.indexOf("Orange") > -1 ) {
    console.log("success");
}

.indexOf() returns the position in the array (or string) of the found element. When no elements are found it returns -1.

Things to consider:

It will return 0 if the first object matches, so you cannot just cast to boolean.
Since es2016 you can use suggestionList.includes('Kiwi'); which will return a boolean directly. (Does not work in internet explorer, but works in IEdge)
includes polyfill for older browsers: https://babeljs.io/docs/usage/polyfill/

edited May 25 '18 at 06:02

answered Apr 22 '16 at 01:07

ippi

"indexOf()" seems to be the answer, thank you, but it really seems like an unintuitive name for "find within", do you know why it's called indexOf? – Gallaxhar Apr 22 '16 at 01:10
Ah, as I just edited in, it's specific use is to find exactly where (the index) the element is in the array, so on the contrary I find the naming quite fitting. As in: The *index of* `orange` in your array is 1. – ippi Apr 22 '16 at 01:13

1 Answers1