Resources

Read or watch:

JavaScript object basics
Object-oriented JavaScript (read all examples!)
Class - ES6
super - ES6
extends - ES6
Object prototypes
Inheritance in JavaScript
Closures
this/self
Modern JS

Learning Objectives

At the end of this project, you are expected to be able to explain to anyone, without the help of Google:

General

Why JavaScript programming is amazing
How to create an object in JavaScript
What this means
What undefined means
Why the variable type and scope is important
What is a closure
What is a prototype
How to inherit an object from another

Requirements

General

Allowed editors: vi, vim, emacs
All your files will be interpreted on Ubuntu 20.04 LTS using node (version 14.x)
All your files should end with a new line
The first line of all your files should be exactly #!/usr/bin/node
A README.md file, at the root of the folder of the project, is mandatory
Your code should be semistandard compliant. Rules of Standard + semicolons on top. Also as reference: AirBnB style
All your files must be executable
The length of your files will be tested using wc
You are not allowed to use var

More Info

Install Node 14

$ curl -sL https://deb.nodesource.com/setup_14.x | sudo -E bash -
$ sudo apt-get install -y nodejs

Install semi-standard

Documentation

$ sudo npm install semistandard --global

Tasks

0. Rectangle #0

Write an empty class Rectangle that defines a rectangle:

You must use the class notation for defining your class

guillaume@ubuntu:~/0x13$ cat 0-main.js
#!/usr/bin/node
const Rectangle = require('./0-rectangle');

const r1 = new Rectangle();
console.log(r1);
console.log(r1.constructor);

guillaume@ubuntu:~/0x13$ ./0-main.js
Rectangle {}
[Class: Rectangle]
guillaume@ubuntu:~/0x13$

Repo:

GitHub repository: alx-higher_level_programming
Directory: 0x13-javascript_objects_scopes_closures
File: 0-rectangle.js

1. Rectangle #1

Write a class Rectangle that defines a rectangle:

You must use the class notation for defining your class
The constructor must take 2 arguments w and h
Initialize the instance attribute width with the value of w
Initialize the instance attribute height with the value of h

guillaume@ubuntu:~/0x13$ cat 1-main.js
#!/usr/bin/node
const Rectangle = require('./1-rectangle');

const r1 = new Rectangle(2, 3);
console.log(r1);
console.log(r1.width);
console.log(r1.height);

const r2 = new Rectangle(2, -3);
console.log(r2);
console.log(r2.width);
console.log(r2.height);

const r3 = new Rectangle(2);
console.log(r3);
console.log(r3.width);
console.log(r3.height);

guillaume@ubuntu:~/0x13$ ./1-main.js
Rectangle { width: 2, height: 3 }
2
3
Rectangle { width: 2, height: -3 }
2
-3
Rectangle { width: 2, height: undefined }
2
undefined
guillaume@ubuntu:~/0x13$

Repo:

GitHub repository: alx-higher_level_programming
Directory: 0x13-javascript_objects_scopes_closures
File: 1-rectangle.js

2. Rectangle #2

Write a class Rectangle that defines a rectangle:

You must use the class notation for defining your class
The constructor must take 2 arguments w and h
Initialize the instance attribute width with the value of w
Initialize the instance attribute height with the value of h
If w or h is equal to 0 or not a positive integer, create an empty object

guillaume@ubuntu:~/0x13$ cat 2-main.js
#!/usr/bin/node
const Rectangle = require('./2-rectangle');

const r1 = new Rectangle(2, 3);
console.log(r1);
console.log(r1.width);
console.log(r1.height);

const r2 = new Rectangle(2, -3);
console.log(r2);
console.log(r2.width);
console.log(r2.height);

const r3 = new Rectangle(2);
console.log(r3);
console.log(r3.width);
console.log(r3.height);

const r4 = new Rectangle(2, 0);
console.log(r4);
console.log(r4.width);
console.log(r4.height);

guillaume@ubuntu:~/0x13$ ./2-main.js
Rectangle { width: 2, height: 3 }
2
3
Rectangle {}
undefined
undefined
Rectangle {}
undefined
undefined
Rectangle {}
undefined
undefined
guillaume@ubuntu:~/0x13$

Repo:

GitHub repository: alx-higher_level_programming
Directory: 0x13-javascript_objects_scopes_closures
File: 2-rectangle.js

3. Rectangle #3

Write a class Rectangle that defines a rectangle:

You must use the class notation for defining your class
The constructor must take 2 arguments: w and h
Initialize the instance attribute width with the value of w
Initialize the instance attribute height with the value of h
If w or h is equal to 0 or not a positive integer, create an empty object
Create an instance method called print() that prints the rectangle using the character X

guillaume@ubuntu:~/0x13$ cat 3-main.js
#!/usr/bin/node
const Rectangle = require('./3-rectangle');

const r1 = new Rectangle(2, 3);
r1.print();

const r2 = new Rectangle(10, 5);
r2.print();

guillaume@ubuntu:~/0x13$ ./3-main.js
XX
XX
XX
XXXXXXXXXX
XXXXXXXXXX
XXXXXXXXXX
XXXXXXXXXX
XXXXXXXXXX
guillaume@ubuntu:~/0x13$

Repo:

GitHub repository: alx-higher_level_programming
Directory: 0x13-javascript_objects_scopes_closures
File: 3-rectangle.js

4. Rectangle #4

Write a class Rectangle that defines a rectangle:

You must use the class notation for defining your class
The constructor must take 2 arguments: w and h
Initialize the instance attribute width with the value of w
Initialize the instance attribute height with the value of h
If w or h is equal to 0 or not a positive integer, create an empty object
Create an instance method called print() that prints the rectangle using the character X
Create an instance method called rotate() that exchanges the width and the height of the rectangle
Create an instance method called double() that multiples the width and the height of the rectangle by 2

guillaume@ubuntu:~/0x13$ cat 4-main.js
#!/usr/bin/node
const Rectangle = require('./4-rectangle');

const r1 = new Rectangle(2, 3);
console.log('Normal:');
r1.print();

console.log('Double:');
r1.double();
r1.print();

console.log('Rotate:');
r1.rotate();
r1.print();

guillaume@ubuntu:~/0x13$ ./4-main.js
Normal:
XX
XX
XX
Double:
XXXX
XXXX
XXXX
XXXX
XXXX
XXXX
Rotate:
XXXXXX
XXXXXX
XXXXXX
XXXXXX
guillaume@ubuntu:~/0x13$

Repo:

GitHub repository: alx-higher_level_programming
Directory: 0x13-javascript_objects_scopes_closures
File: 4-rectangle.js

5. Square #0

Write a class Square that defines a square and inherits from Rectangle of 4-rectangle.js:

You must use the class notation for defining your class and extends
The constructor must take 1 argument: size
The constructor of Rectangle must be called (by using super())

guillaume@ubuntu:~/0x13$ cat 5-main.js
#!/usr/bin/node
const Square = require('./5-square');

const s1 = new Square(4);
s1.print();
s1.double();
s1.print();

guillaume@ubuntu:~/0x13$ ./5-main.js
XXXX
XXXX
XXXX
XXXX
XXXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXX
guillaume@ubuntu:~/0x13$

Repo:

GitHub repository: alx-higher_level_programming
Directory: 0x13-javascript_objects_scopes_closures
File: 5-square.js

6. Square #1

Write a class Square that defines a square and inherits from Square of 5-square.js:

You must use the class notation for defining your class and extends
Create an instance method called charPrint(c) that prints the rectangle using the character c
- If c is undefined, use the character X

guillaume@ubuntu:~/0x13$ cat 6-main.js
#!/usr/bin/node
const Square = require('./6-square');

const s1 = new Square(4);
s1.charPrint();

s1.charPrint('C');

guillaume@ubuntu:~/0x13$ ./6-main.js
XXXX
XXXX
XXXX
XXXX
CCCC
CCCC
CCCC
CCCC
guillaume@ubuntu:~/0x13$

Repo:

GitHub repository: alx-higher_level_programming
Directory: 0x13-javascript_objects_scopes_closures
File: 6-square.js

7. Occurrences

Write a function that returns the number of occurrences in a list:

Prototype: exports.nbOccurences = function (list, searchElement)

guillaume@ubuntu:~/0x13$ cat 7-main.js
#!/usr/bin/node
const nbOccurences = require('./7-occurrences').nbOccurences;

console.log(nbOccurences([1, 2, 3, 4, 5, 6], 3));
console.log(nbOccurences([3, 2, 3, 4, 5, 3, 3], 3));
console.log(nbOccurences(["S", 12, "c", "S", "School", 8], "S"));

guillaume@ubuntu:~/0x13$ ./7-main.js
1
4
2
guillaume@ubuntu:~/0x13$

Repo:

GitHub repository: alx-higher_level_programming
Directory: 0x13-javascript_objects_scopes_closures
File: 7-occurrences.js

8. Esrever

Write a function that returns the reversed version of a list:

Prototype: exports.esrever = function (list)
You are not allow to use the built-in method reverse

guillaume@ubuntu:~/0x13$ cat 8-main.js
#!/usr/bin/node
const esrever = require('./8-esrever').esrever;

console.log(esrever([1, 2, 3, 4, 5]));
console.log(esrever(["School", 89, { id: 12 }, "String"]));

guillaume@ubuntu:~/0x13$ ./8-main.js
[ 5, 4, 3, 2, 1 ]
[ 'String', { id: 12 }, 89, 'School' ]
guillaume@ubuntu:~/0x13$

Repo:

GitHub repository: alx-higher_level_programming
Directory: 0x13-javascript_objects_scopes_closures
File: 8-esrever.js

9. Log me

Write a function that prints the number of arguments already printed and the new argument value. (see example below)

Prototype: exports.logMe = function (item)
Output format: <number arguments already printed>: <current argument value>

guillaume@ubuntu:~/0x13$ cat 9-main.js
#!/usr/bin/node
const logMe = require('./9-logme').logMe;

logMe("Hello");
logMe("Best");
logMe("School");

guillaume@ubuntu:~/0x13$ ./9-main.js
0: Hello
1: Best
2: School
guillaume@ubuntu:~/0x13$

Repo:

GitHub repository: alx-higher_level_programming
Directory: 0x13-javascript_objects_scopes_closures
File: 9-logme.js

10. Number conversion

Write a function that converts a number from base 10 to another base passed as argument:

Prototype: exports.converter = function (base)
You are not allowed to import any file
You are not allowed to declare any new variable (var, let, etc..)

guillaume@ubuntu:~/0x13$ cat 10-main.js
#!/usr/bin/node
const converter = require('./10-converter').converter;

let myConverter = converter(10);

console.log(myConverter(2));
console.log(myConverter(12));
console.log(myConverter(89));


myConverter = converter(16);

console.log(myConverter(2));
console.log(myConverter(12));
console.log(myConverter(89));

guillaume@ubuntu:~/0x13$ ./10-main.js
2
12
89
2
c
59
guillaume@ubuntu:~/0x13$

Repo:

GitHub repository: alx-higher_level_programming
Directory: 0x13-javascript_objects_scopes_closures
File: 10-converter.js

11. Factor index

Write a script that imports an array and computes a new array.

Your script must import list from the file 100-data.js
You must use a map. Tips
A new list must be created with each value equal to the value of the initial list, multipled by the index in the list
Print both the initial list and the new list

guillaume@ubuntu:~/0x13$ cat 100-data.js
#!/usr/bin/node
exports.list = [1, 2, 3, 4, 5];
guillaume@ubuntu:~/0x13$ ./100-map.js
[ 1, 2, 3, 4, 5 ]
[ 0, 2, 6, 12, 20 ]
guillaume@ubuntu:~/0x13$

Repo:

GitHub repository: alx-higher_level_programming
Directory: 0x13-javascript_objects_scopes_closures
File: 100-map.js

12. Sorted occurences

Write a script that imports a dictionary of occurrences by user id and computes a dictionary of user ids by occurrence.

Your script must import dict from the file 101-data.js
In the new dictionary:
- A key is a number of occurrences
- A value is the list of user ids
Print the new dictionary at the end

guillaume@ubuntu:~/0x13$ cat 101-data.js
#!/usr/bin/node
exports.dict = {
  89: 1,
  90: 2,
  91: 1,
  92: 3,
  93: 1,
  94: 2
};
guillaume@ubuntu:~/0x13$ ./101-sorted.js
{ '1': [ '89', '91', '93' ], '2': [ '90', '94' ], '3': [ '92' ] }
guillaume@ubuntu:~/0x13$

Repo:

GitHub repository: alx-higher_level_programming
Directory: 0x13-javascript_objects_scopes_closures
File: 101-sorted.js

13. Concat files

Write a script that concats 2 files.

The first argument is the file path of the first source file
The second argument is the file path of the second source file
The third argument is the file path of the destination

guillaume@ubuntu:~/0x13$ cat fileA
C is fun!
guillaume@ubuntu:~/0x13$ cat fileB
Python is Cool!!!
guillaume@ubuntu:~/0x13$ ./102-concat.js fileA fileB fileC
guillaume@ubuntu:~/0x13$ cat fileC
C is fun!
Python is Cool!!!
guillaume@ubuntu:~/0x13$

Repo:

GitHub repository: alx-higher_level_programming
Directory: 0x13-javascript_objects_scopes_closures
File: 102-concat.js

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README.md

README.md

Resources

Read or watch:

Learning Objectives

General

Requirements

General

More Info

Install Node 14

Install semi-standard

Tasks

0. Rectangle #0

1. Rectangle #1

2. Rectangle #2

3. Rectangle #3

4. Rectangle #4

5. Square #0

6. Square #1

7. Occurrences

8. Esrever

9. Log me

10. Number conversion

11. Factor index

12. Sorted occurences

13. Concat files

Files

README.md

Latest commit

History

README.md

File metadata and controls

Resources

Read or watch:

Learning Objectives

General

Requirements

General

More Info

Install Node 14

Install semi-standard

Tasks

0. Rectangle #0

1. Rectangle #1

2. Rectangle #2

3. Rectangle #3

4. Rectangle #4

5. Square #0

6. Square #1

7. Occurrences

8. Esrever

9. Log me

10. Number conversion

11. Factor index

12. Sorted occurences

13. Concat files