Answers for "indexof element in array javascrip"

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);

JavaScript Array Methods indexOf()

let days = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday'];
console.log(days.indexOf('Sunday'));
// --> -1, mert nem található meg

let days = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday'];
console.log(days.indexOf('Monday'));
// --> 0