js indexof in array code example
Example 1: javascript indexOf object value in array
const needle = 3;
const haystack = [{ id: 1 }, { id: 2 }, { id: 3 }];
const index = haystack.findIndex(item => item.id === needle);
Example 2: get index of element in array js
const beasts = ['ant', 'bison', 'camel', 'duck', 'bison'];
console.log(beasts.indexOf('bison'));
console.log(beasts.indexOf('bison', 2));
console.log(beasts.indexOf('giraffe'));
Example 3: javasript array indexof
var array = [2, 9, 9];
array.indexOf(2);
array.indexOf(7);
array.indexOf(9, 2);
array.indexOf(2, -1);
array.indexOf(2, -3);
Example 4: get index of element in array javascript
var scores = [10, 20, 30, 10, 40, 20];
console.log(scores.indexOf(30));
console.log(scores.indexOf(50));
Example 5: indexof javascript
Array.indexOf(searchElement, fromIndex)