exercises.js

'use strict';

//Do not change any of the function names

function makeCat(name, age) {
  //create a new object with a name property with the value set to the name argument
  //add an age property to the object with the value set to the age argument
  //add a method called meow that returns the string 'Meow!'
  //return the object
    var cat = {
        name: name,
        age: age,
        meow: function() {
            return 'Meow!';
        } // end meow method
    }; // end object cat
    return cat;
}

function addProperty(object, property) {
  //add the property to the object with a value of null
  //return the object
  //note: the property name is NOT 'property'.  The name is the value of the argument called property (a string)
    object[property] = null;
    return object;
}

function invokeMethod(object, method) {
  //method is a string that contains the name of a method on the object
  //invoke this method
  //nothing needs to be returned
    object[method]();
}

function multiplyMysteryNumberByFive(mysteryNumberObject) {
  //mysteryNumberObject has a property called mysteryNumber
  //multiply the mysteryNumber property by 5 and return the product
    return mysteryNumberObject.mysteryNumber * 5;
}

function deleteProperty(object, property) {
  //remove the property from the object
  //return the object
    delete object[property];
    return object;
}

function newUser(name, email, password) {
  //create a new object with properties matching the arguments passed in.
  //return the new object
    var obj = {
        name: name,
        email: email,
        password: password
    };
    return obj;
}

function hasEmail(user) {
  //return true if the user has a value for the property 'email'
  //otherwise return false
    if (user.email) return true;
    else return false;
}

function hasProperty(object, property) {
  //return true if the object has the value of the property argument
  //property is a string
  //otherwise return false
    if (object.hasOwnProperty(property)) return true;
    else return false;
}

function verifyPassword(user, password) {
  //check to see if the provided password matches the password property on the user object
  //return true if they match
  //otherwise return false
    if (user.password === password) return true;
    else return false;
}

function updatePassword(user, newPassword) {
  //replace the existing password on the user object with the value of newPassword
  //return the object
    user.password = newPassword;
    return user;
}

function addFriend(user, newFriend) {
  //user has a property called friends that is an array
  //add newFriend to the end of the friends array
  //return the user object
    user.friends.push(newFriend);
    return user;
}

function setUsersToPremium(users) {
  //users is an array of user objects.
  //each user object has the property 'isPremium'
  //set each user's isPremium property to true
  //return the users array
    for (var i in users) {
        users[i].isPremium = true;
    } // end for
    return users;
}

function sumUserPostLikes(user) {
  //user has an array property called 'posts'
  //posts is an array of post objects
  //each post object has an integer property called 'likes'
  //sum together the likes from all the post objects
  //return the sum
    var sum = 0;
    for (var i in user.posts) {
        sum += user.posts[i].likes;
    } // end for
    return sum;
}

function addCalculateDiscountPriceMethod(storeItem) {
  //add a method to the storeItem object called 'calculateDiscountPrice'
  //this method should multiply the storeItem's 'price' and 'discountPercentage' to get the discount
  //the method then subtracts the discount from the price and returns the discounted price
  //example: 
  //price -> 20
  //discountPercentage -> .2
  //discountPrice = 20 - (20 * .2)
    
    // return storeItem
    
    storeItem.calculateDiscountPrice = function() {
       return storeItem.price - (storeItem.price * storeItem.discountPercentage);
    };
    
    return storeItem;
}

//Do not modify code below this line.
////--------------------------------

module.exports = {
  makeCat: makeCat,
  addProperty: addProperty,
  invokeMethod: invokeMethod,
  multiplyMysteryNumberByFive: multiplyMysteryNumberByFive,
  deleteProperty: deleteProperty,
  newUser: newUser,
  hasEmail: hasEmail,
  hasProperty: hasProperty,
  verifyPassword: verifyPassword,
  updatePassword: updatePassword,
  addFriend: addFriend,
  setUsersToPremium: setUsersToPremium,
  sumUserPostLikes: sumUserPostLikes,
  addCalculateDiscountPriceMethod: addCalculateDiscountPriceMethod
};