app.js

/* 
Write a function called `findUserByUsername` which accepts an array of objects, each with a key of username,
 and a string. The function should return the first object with the key of username that matches the string
  passed to the function. If the object is not found, return undefined. 

const users = [
  {username: 'mlewis'},
  {username: 'akagen'},
  {username: 'msmith'}
];

findUserByUsername(users, 'mlewis') // {username: 'mlewis'}
findUserByUsername(users, 'taco') // undefined
*/


function findUserByUsername(usersArray, username) {
    return usersArray.find(function (obj) {
        return obj.username === username;
    })
}

/*
Write a function called `removeUser` which accepts an array of objects, 
each with a key of username, and a string. The function should remove the 
object from the array. If the object is not found, return undefined. 

const users = [
  {username: 'mlewis'},
  {username: 'akagen'},
  {username: 'msmith'}
];

removeUser(users, 'akagen') // {username: 'akagen'}
removeUser(users, 'akagen') // undefined
*/

function removeUser(usersArray, username) {
    let foundIndex = usersArray.findIndex(function (user) {
        return user.username === username;
    })
    if (foundIndex === -1) return;

    return usersArray.splice(foundIndex, 1)[0];
}