Just some beginner practice problems for Elm.

elm-challanges.md

Elm practice problems

Problems

1 Simple functions

• 1. 1 Write a function that takes an Integer and returns True or False depending on whether the number is greater than 12.

• 1. 2 Write a function that takes an Integer and returns True or False depending on whether it is odd. Look up the % operator

• 1. 3 Write a function that takes a name as a String and returns "Hello, Name!". Look up the ++ operator.

  greet "Bob" -> "Hello, Bob!"
  greet "Carl" -> "Hello, Carl!"
  

• 1. 4 Write a function that takes two numbers and return their sum.

• 1. 5 Write a function that takes tree numbers and takes the largest one. Hint: use max

• 1. 6 Write a function that takes two numbers returning their product.

• 1. 7 Write a function that takes a function and two numbers, applies it to the two numbers and then returns the sum of the two results.

• 1. 8 Write a function that takes an argument, ignores it and return 12

• 1. 9 Write a function that takes 3 arguments and return the product of the two biggest ones.

• 1. 10 Write a function that calculates the area of any given square.

• 1. 11 Write a function that calculates the area of any given triangle.

• 1. 12 Write a function that solves an equation of form 0=x^2+px+q.

• 1. 13 Write a function that get a number's absolute value.

• 1. 14 Write a function that sees if a number's divisble by another.

• 1. 15 Write a function that calculates a number's squareroot and uses a Maybe to ensure against failure.

• 1. 16 Write a function that gets the avarage of any given two numbers.

2 A bit more complicated functions

• 2. 1 Write a function that gets the factorial of any given number.
• 2. 2 Write a function that gets the avarage of any list of numbers.
• 2. 3 Write a function that calculates the digit sum of any given two digit integer.
• 2. 4 Write a function that calculates the sum of any given list of numbers.
• 2. 5 Write a function that calculates the nth power of any given number.

Solutions

1 Simple functions

• 1. 1

  greaterThan12 x = x > 12

• 1. 2

  isOdd x = (x % 2) /= 0

• 1. 3

  greet name = "Hello, " ++ name ++ "!"

• 1. 4

  getSum x y = x + y

• 1. 5

  largestOfThree x y z = max (max x y) z

• 1. 6

  getProduct x y = x * y

• 1. 7

  applyFunctionAndGetSum func n1 n2 = (func n1) + (func n2)

• 1. 8

  ignoreArg x = 12

• 1. 9

  productOfGreatest x y z = (x * y * z) / (min x (min y z))

2 A bit more complicated functions

• 2. 1

  factorial n = if n == 0 then 1 else n * factorial (n-1)