MoN Oct. 16

Introduction to Programming & JS

9 – 12h Teaching

Teacher:

  • Jörg Wasmeier

Goals

  • I understand the basic concepts of programming with JavaScript
  • I know the primitive data types and can tell the difference between null and undefined
  • I know how to declare variables & functions and add comments
  • I understand and can explain the following terms: global scope, local scope, argument, return value

Intro to Programming

Slides: Intro to Programming

Included Exercises

12 – 13.30h Lunch

13.30 – 17h Coaching

Coaches:


Learning by Doing

Function & Math Exercises

The Calculator

Read through the exercises first, then start solving them on repl.it.

  • Write a function called squareNumber that will take one argument (a number), square that number, and return the result. It should also log a string like "The result of squaring the number 3 is 9."
  • Write a function called halfNumber that will take one argument (a number), divide it by 2, and return the result. It should also log a string like "Half of 5 is 2.5.".
  • Write a function called percentOf that will take two numbers, figure out what percent the first number represents of the second number, and return the result. It should also log a string like "2 is 50% of 4."
  • Write a function called areaOfCircle that will take one argument (the radius), calculate the area based on that, and return the result. It should also log a string like "The area for a circle with radius 2 is 12.566370614359172."
    • Bonus: Round the result so there are only two digits after the decimal.
  • Write a function that will take one argument (a number) and perform the following operations, using the functions you wrote earlier1:
    1. Take half of the number and store the result.
    2. Square the result of #1 and store that result.
    3. Calculate the area of a circle with the result of #2 as the radius.
    4. Calculate what percentage that area is of the squared result (#3).
    5. Return the result

[ Source | Solutions on repl.it ]

Don't forget...

    • ...to take breaks (every 30mins)
    • ...to ask for help if you're stuck!

String Exercises

You can use the JavaScript editor / environment of your choice.

We recommend using repl.it for solving these exercises.

DrEvil

Create a function called DrEvil. It should take a single argument, an amount, and return '<amount> dollars', except it will add '(pinky)' at the end if the amount is 1 million. For example:

  DrEvil(10): 10 dollars
  DrEvil(1000000): 1000000 dollars (pinky)

MixUp

Create a function called mixUp. It should take in two strings, and return the concatenation of the two strings (separated by a space) slicing out and swapping the first 2 characters of each. You can assume that the strings are at least 2 characters long. For example:

  mixUp('mix', pod'): 'pox mid'
  mixUp('dog', 'dinner'): 'dig donner'

Look up the JavaScript string reference to find methods which may be useful!

FixStart

Create a function called fixStart. It should take a single argument, a string, and return a version where all occurences of its first character have been replaced with '*', except for the first character itself. You can assume that the string is at least one character long. For example:

fixStart('babble'): 'ba**le'

Verbing

Create a function called verbing. It should take a single argument, a string. If its length is at least 3, it should add 'ing' to its end, unless it already ends in 'ing', in which case it should add 'ly' instead. If the string length is less than 3, it should leave it unchanged. For example:

  verbing('swim'): 'swimming'
  verbing('swimming'): 'swimmingly'
  verbing('go'): 'go'

Not Bad

  • Create a function called notBad that takes a single argument, a string.
  • It should find the first appearance of the substring 'not' and 'bad'.
  • If the 'bad' follows the 'not', then it should replace the whole 'not'...'bad' substring with 'good' and return the result.
  • If it doesn't find 'not' and 'bad' in the right sequence (or at all), just return the original sentence.

For example:

  notBad('This dinner is not that bad!'): 'This dinner is good!'
  notBad('This movie is not so bad!'): 'This movie is good!'
  notBad('This dinner is bad!'): 'This dinner is bad!'


[ Source | Solutions on repl.it ]