indexof elelment in array code example
Example 1: how to find the index of a value in an array in javascript
var list = ["apple","banana","orange"]
var index_of_apple = list.indexOf("apple") // 0
Example 2: javasript array indexof
var array = [2, 9, 9];
array.indexOf(2); // 0
array.indexOf(7); // -1
array.indexOf(9, 2); // 2
array.indexOf(2, -1); // -1
array.indexOf(2, -3); // 0