javascript return index of object with key code example

Example 1: javascript get index of object 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: indexOf by object key

var index = peoples.findIndex(p => p.attr1 == "john")