javascript indexof element in array code example
Example 1: javascript indexOf object value in array
// Get index of object with specific value in array
const needle = 3; // needle
const haystack = [{ id: 1 }, { id: 2 }, { id: 3 }]; // haystack
const index = haystack.findIndex(item => item.id === needle);
Example 2: 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 3: 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 4: get index of element in array javascript
var scores = [10, 20, 30, 10, 40, 20];
console.log(scores.indexOf(30)); // 2
console.log(scores.indexOf(50)); // -1
Example 5: indexof javascript
arr.indexOf(searchElement[, fromIndex])