// 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);
arr = [{x: "a", y: 1}, {x: "something", y: 2}]
arr.findIndex(obj => obj.x === "a" && obj.y === 1);