get index of value in array js code example

Example 1: javascript get index of object with value in array

// Get index of object with specific value in array
const needle = 3;
const haystack = [{ id: 1 }, { id: 2 }, { id: 3 }];
const index = haystack.findIndex(item => item.id === needle);

Example 2: js get index of item in array

array.indexOf("item");

Example 3: 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 4: how to get the index of an array in javascript

search = (arr, item) => { return arr.indexOf(item); }

Example 5: access index of array javascript

let first = fruits[0]
// Apple

let last = fruits[fruits.length - 1]
// Banana