rest-spread-exercise.js

///////////////////////////////////////////////ES2015version/////////////////////////////////////////////////
// function filterOutOdds() {
//     var nums = Array.prototype.slice.call(arguments);
//     return nums.filter(function(num) {
//       return num % 2 === 0
//     });
//   }
  /* Write an ES2015 Version */

const filterOutOdds = (...arguments) =>
    arguments.filter(nums => nums % 2 === 0);

///////////////////////////////////////////////findMin/////////////////////////////////////////////////
//   findMin(1,4,12,-3) // -3
//   findMin(1,-1) // -1
//   findMin(3,1) // 1

// function findMin (...args) {
//     return args.reduce((val, nextVal) => 
//          val < nextVal ? val : nextVal
//         )
// }

const findMin = (...args) => Math.min(...args);

///////////////////////////////////////////////mergeObjects/////////////////////////////////////////////////
//Write a function called mergeObjects that accepts two objects and 
//returns a new object which contains all the keys and values of the first object and second object.
//mergeObjects({a:1, b:2}, {c:3, d:4}) // {a:1, b:2, c:3, d:4} 

const mergeObjects = (obj1, obj2) => ({...obj1, ...obj2});

///////////////////////////////////////////////doubleAndReturnArgs/////////////////////////////////////////////////
//Write a function called doubleAndReturnArgs which accepts an array and a variable number of arguments. 
//The function should return a new array with the original array values and all of additional arguments doubled.
//doubleAndReturnArgs([1,2,3],4,4) // [1,2,3,8,8]
//doubleAndReturnArgs([2],10,4) // [2, 20, 8]

const doubleAndReturnArgs = (arr, ...args) => [...arr, ...args.map((num) => num * 2)];

///////////////////////////////////////////////SliceAndDice!/////////////////////////////////////////////////
// For this section, write the following functions using rest, spread and refactor these functions to be arrow functions!
// Make sure that you are always returning a new array or object and not modifying the existing inputs.

/** remove a random element in the items array
and return a new array without that item. */

const removeRandom = items => {
    const index = Math.round(items.length / (Math.random() * 10));
    return [...items.slice(0, index), ...items.slice(index + 1)];
}

/** Return a new array with every item in array1 and array2. */

const extend = (array1, array2) => [...array1, ...array2];


/** Return a new object with all the keys and values
from obj and a new key/value pair */

const object = {
    item: "tree",
    branches: "no"
};

const addKeyVal = (obj, key, val) => {
    const newObj = {...obj};
    newObj[key] = val; 
    return newObj;
}


/** Return a new object with a key removed. */

const removeKey = (obj, key) => {
    const newObj = {...obj};
    delete newObj[key];
    return newObj;
}


/** Combine two objects and return a new object. */

const chickenObj = {
    item: "chicken",
    price: 11.39,
    quantity: 3
}
const teaObj = {
    item: "bucket",
    price: 5.99,
    quantity: 1
}

const combine = (obj1, obj2) => newObj = {...obj1, ...obj2};



/** Return a new object with a modified key and value. */

const update = (obj, key, val) => {
    newObj = {...obj};
    newObj[key] = val;
    return newObj;
}