`array.find()` and `array.findIndex()` do pretty much what you expect. They go over each item of an array so you can return the value you want, which is especially handy when you're looking for something in particular in an array of objects (and even more handy when that array of objects is keyless. Example time

es6-find-findindex.js

  const users = [
    {
        "_id": "5a0b7a6441a687091332f11b",
        "index": 0,
        "guid": "0d3bba05-ecde-4237-b53e-0bd474239ee2",
        "isActive": false,
        "balance": "$2,144.22",
        "picture": "http://placehold.it/32x32",
        "age": 32,
        "eyeColor": "green",
        "name": "Lavonne Finley",
        "gender": "female"
    },
    {
        "_id": "5a0b7a647febf037be5daaa7",
        "index": 1,
        "guid": "20311487-7e92-48ba-a26f-d627d7cb3686",
        "isActive": false,
        "balance": "$2,284.92",
        "picture": "http://placehold.it/32x32",
        "age": 21,
        "eyeColor": "blue",
        "name": "Austin Mullins",
        "gender": "male"
    },
    {
        "_id": "5a0b7a64ed89bcc74e06d289",
        "index": 2,
        "guid": "211f93e7-73b9-46a5-80db-bc04908af917",
        "isActive": false,
        "balance": "$1,581.91",
        "picture": "http://placehold.it/32x32",
        "age": 32,
        "eyeColor": "brown",
        "name": "Henderson Bryant",
        "gender": "male"
    },
    {
        "_id": "5a0b7a64fdb857c6a2b5767a",
        "index": 3,
        "guid": "2e1e89de-06c2-45dd-b92e-afb4a9702026",
        "isActive": true,
        "balance": "$3,069.90",
        "picture": "http://placehold.it/32x32",
        "age": 35,
        "eyeColor": "blue",
        "name": "Mia House",
        "gender": "female"
    }
]

// Return the user with the matching id
const user = users.find(user => user._id === '5a0b7a64ed89bcc74e06d289');
console.log(user);

// Return the index of the user with the matching ID
const userIndex = users.findIndex(user => user._id === '5a0b7a64ed89bcc74e06d289');
console.log(userIndex);