how to check content of item in array javascript code example

Example 1: javascript is int in array

[1, 2, 3].includes(2);     // true
[1, 2, 3].includes(4);     // false
[1, 2, 3].includes(1, 2);  // false (second parameter is the index position in this array at which to begin searching)

Example 2: how to check if item is in list js

var myList=["a", "b", "c"];
mylist.includes("d")//returns true or false