Find a Substring in a JavaScript Array

find-sub-str-in-arr.js

// The bitwise NOT (~) operator inverts the -1 to 0, and the !! operator coerces that value to false when the string is not in the array.
var arr = ['foo', 'bar'];
var str = 'baz';
var isTrue = !!~arr.indexOf(str); // return false
str = 'foo';
isTrue = !!~arr.indexOf(str); // return true

// Which is essentially a one-liner for this:
var isTrue = true;
if (arr.indexOf(str) === -1) {
  isTrue = false;
}

// Or, you can use ES2015’s Array.protoype.find() (with a Polyfill if required).
var arr = ['foo', 'bar'];
var str = 'food.land';
var isTrue = !!arr.find(function (elem) {
  return !!~str.indexOf(elem); // return true
});