check indexof array code example
Example 1: index of value in array
// for dictionary case use findIndex
var imageList = [
{value: 100},
{value: 200},
{value: 300},
{value: 400},
{value: 500}
];
var index = imageList.findIndex(img => img.value === 200);
Example 2: js array get index
var fruits = ["Banana", "Orange", "Apple", "Mango"];
return fruits.indexOf("Apple"); // Returns 2