indexOf mdn code example

Example 1: javascript indexof

//indexOf getting index of array element, returns -1 if not found
var colors=["red","green","blue"];
var pos=colors.indexOf("blue");//2

//indexOf getting index of sub string, returns -1 if not found
var str = "We got a poop cleanup on isle 4.";
var strPos = str.indexOf("poop");//9

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

Example 3: indefOf

const beasts = ['ant', 'bison', 'camel', 'duck', 'bison'];

console.log(beasts.indexOf('bison'));
// expected output: 1

Example 4: indexof javascript

arr.indexOf(searchElement[, fromIndex])

Example 5: indexof js mdn

array.indexOf(searchElement, [initialPoint = 0])

// the indexOf() always returns the first index that the element can be found, else it returns -1