practice.js

/*
  Once you complete a problem, refresh ./nesting.html in your browser and check to see if the problem's test(s) are passing.
  Passed tests will be indicated by a green circle.
  Failed tests will be indicated by a red X.

  You can refresh the page at any time to re-run all the tests.
*/

////////// FOR IN LOOPS //////////

////////// PROBLEM 1 //////////

// Do not edit the code below.
const number = {
    age: 30,
	score: 100,
	length: 12,
	year: 2016,
};

// Do not edit the code above.

/*
Here we have a function called objectLooper that will take a number object and loop over it
Inside this loop, change the value of each property to 0
*/

function objectLooper(number) {
    for (let key in number) {
        // Code here
    }
    return number;
};


////////// PROBLEM 2 //////////

// Do not edit the code below.
const state = {
    utah: 2942902,
    texas: 26956958,
    california: 38802500,
};

// Do not edit the code above.

/*
Check each value inside the pre-written for in loop
If a value is greater than 3,000,000 set it to 0
*/

function stateLooper(obj) {
	for (let key in obj) {
		// Code here
	}
	return obj;
};


////////// PROBLEM 3 //////////

/*
Here is a function named cleanUser that will be passed an object
Inside of this function, loop over the object so that every property with a falsy value is removed
Once all falsy values and their properties are removed, return the object
*/

function cleanUser(obj) {
    // Code here
};


////////// PROBLEM 4 //////////

/*
Create a function called maxedOut that takes a user object and loops over that object to change all the object property values to "max"
Return the updated user object
*/

// Code here



////////// OBJECT DESTRUCTURING //////////

/*
Object destructuring allows you to "unpack" properties from objects and assign them to variables
An example of this is the object numbers as seen in the code
On line 96, the variables one, two and three are receiving the property values from the numbers object
This is the process called destructuring
*/

// const numbers = {
    // 	one: "1",
    // 	two: "2",
    // 	three: "3",
    // };
    
// const { one, two, three } = numbers;
    
    
////////// PROBLEM 5 //////////
    
// Do not edit the code below.
var animalCount = {
    cats: 2,
    dogs: 5,
    mice: 0,
};

// Do not edit the code above.
    
/*
Above you are given the object animalCount
Destructure this object so that you have 3 distinct variables with values matching those of the properties from animalCount
*/

// Code here



////////// PROBLEM 6 //////////

/*
Now that you have some experience with destructuring, we will take it one step further
Instead of using a variable to assign values, we will use an object literal
The commented code below is an example of this
*/

// const {one, two, three} = {one: '1', two: '2', three: '3'}

/*
For this problem, create an object literal to assign variables a value through destructuring
These variables should be: students, mentors and instructors
Set the value of students to be 24, mentors to be 3, and instructors to be 5
*/

// Code here



////////// PROBLEM 7 //////////

/*
Create an object named languages with the properties 'french', 'english' and 'spanish'
Give these properties the value true if you speak the language or false if you do not
Use destructuring to assign the values of these properties to new variables
*/

// Code here



////////// PROBLEM 8 //////////

/*
We will now be implementing object destructuring using functions
See the below commented code for an example

Here we have an object called nums and a function called addition
In this function, we are using object destructuring to unpack the objects values and assign them to new variables
We then will add these values together and return the result
If we were to invoke the addition function and pass in the nums object, the returned value would be 6
*/

// const nums = {
//   one: 1,
//   two: 2,
//   three: 3
// }

// const addition = (obj) => {
//   const {one, two, three} = obj;
//   const total = one + two + three;
//   return total
// }

/*
For this problem, write a function called subtraction with an object parameter
The object passed in this function will have the property names num1 and num2
In the function, use object destructuring to assign the values of these properties to new variables
Subtract num2 from num1 and return the result
*/

// Code here



////////// PROBLEM 9 //////////

/*
Create a function called zooAnimals that will take an object parameter
The object passed to this function will have the property names lion, tiger, and bear
The values of these properties will be a number representing the count of that animal in the zoo
Using object destructuring, return the total sum of the counts of these animals
*/

// Code here



////////// PROBLEM 10 //////////

/*
Now that you've practiced object destructuring inside of a function with that function's parameter, we will take it one step further
Instead of using object destructuring inside of the function, we can declare a destructured object as our parameter
See below for an example
The function immediatelyDestructured has a parameter that is a destructured object
This is useful because we can immediately use the variables one, two and three in the function instead of having to destructure the object parameter inside of the function
If we were to invoke the function and pass in the exampleObj object below, the returned value would be 6
*/

// const exampleObj = {one: 1, two: 2, three: 3}

// const immediatelyDestructured = ({one, two, three}) => {
//   return one + two + three
// }

/*
For this problem, write a function called greeting
Instead of giving it an object parameter, give it a destructured object as it's parameter
The properties of this object will be name and title
Return from this function a greeting sentence that should say "Hello, <title> <name>!"
Title and name in this sentence should be replaced with the values of the destructured object variables 
*/

// Code here



////////// PROBLEM 11 //////////

/*
Create a function called truthyFalsy that takes a destructured object as it's parameter
The properties of this object will be number and string
One of these properties will be truthy and the other will be falsy
Return the value that is truthy
*/

// Code here



////////// PROBLEM 12 //////////

/*
Create a one line ES6 arrow function called isGreaterThanTwenty that will take in a single parameter
The function should return true if the parameter is greater than 20 and should return false otherwise  

You should not use the ES5 function declaration or function expression syntax in your final solution
Your function should also be contained within a single line
*/

// Code here



////////// PROBLEM 13 //////////

/*
Create a one line arrow function called seven that will return the number 7

You should not use the ES5 function declaration or function expression syntax in your final solution
Your function should also be contained within a single line
*/

// Code here



////////// PROBLEM 14 //////////

/*
Re-write the commented out ES5 functions provided below as ES6 arrow functions
Name your functions the same as the ES5 versions provided below
 
You should not use the ES5 function declaration or function expression syntax in your final solution
Your function should also be contained within a single line
*/

/*
function add(num1, num2) {
    return num1 + num2;
};

function subtract(num1, num2) {
    return num1 - num2;
};

function double(num) {
    return num * 2;
};
*/

// Code here



////////// PROBLEM 15 //////////

/*
Create an ES6 arrow function called multiply that takes in two parameters: num1 and num2
The function should return the product of the two parameters

You should not use the ES5 function declaration or function expression syntax in your final solution
*/

// Code here



////////// PROBLEM 16 //////////

/*
Create an ES6 arrow function called concatenate that takes in two parameters: str1 and str2
The function should return a single concatenated (joined) str of str1 and str2

You should not use the ES5 function declaration or function expression syntax in your final solution
*/

// Code here



////////// PROBLEM 17 //////////

/*
Write an arrow function called gemInfo that takes in three parameters: gemType, gemSize, and gemWeight
The function should return an object with the properties: gemType, gemSize, gemWeight
The values of each property should correspond to its respective parameter

You should not use the ES5 function declaration or function expression syntax in your final solution
*/

// Code here



////////// PROBLEM 18 //////////

/*
Create a function called identifier that uses the filter higher order array method to filter over the provided jobs array of objects
The function should return the object of the person with a job as a programmer
Make sure to use the arrow function in conjunction with the filter method

Your returned value should be a single object, not an array with one object inside of it
You should not use the ES5 function declaration or function expression syntax in your final solution
You should not use a for loop, but should use the filter method instead
*/

// Do not edit the code below.
let jobs = [
	{ receptionist: "James" },
	{ programmer: "Steve" },
	{ designer: "Alicia" },
];

// Do not edit the code above.


// Code here



////////// PROBLEM 19 //////////

/*
Create a function called evens that takes in an array as a parameter
The function should use the filter method to filter over the array parameter and return a new array with only the even numbers included
Make sure to use the arrow function construct combined with the higher order array filter method
  
You should not use the ES5 function declaration or function expression syntax in your final solution
You should not use a for loop, but should use the filter method instead
*/

// Code here



////////// PROBLEM 20 //////////

/*
Create a function called startWithLetterA that takes in an array as a parameter
The function should use the filter method to filter over the array of strings and return a new array with only the strings that start with the letter "A" or "a"
The filter is not case-sensitive, so it should return words that begin with both "A" and "a"
Make sure to use the arrow function construct combined with the higher order array filter method
  
You should not use the ES5 function declaration or function expression syntax in your final solution
You should not use a for loop, but should use the filter method instead

*/

// Code here



////////// PROBLEM 21 //////////

/*
Edit the formalGreeting function and use the built in .map method to map over the names parameter
and return a new array with "Hello, " appended to the beginning of each name
Make sure to use arrow functions combined with the map method    

*/

const formalGreeting = names => {
    // Code here
}



////////// PROBLEM 22 //////////

/*
Edit the productOfArray function and use the built in .reduce method to loop over the numbers parameter
and return the product of all the numbers in the array
Make sure to use arrow functions combined with the reduce method    

*/

const productOfArray = numbers => {
    // Code here
}