Coding Adelante: Challenges

adelante.md

Coding Adelante: Challenges

Hello, world!

1. Write a function called hello that prints "Hello, world!" in the console.

   function hello() {
       ...
   }
       
   hello()
   //  Hello, world!

2. Write a function that takes a name and prints "Hello, " followed by the name:

   function hello(name) { ... }
       
   hello('Herb')
   //  Hello, Herb!

3. Write a function that takes two names and says hello to both of them:

   function hello(name1, name2) { ... }
   
   hello('Herb', 'Georgi')
   // Hello, Herb and Georgi!

4. Write a function that takes one or two names. If two names are provided, say hello to both of them. Otherwise, say hello to just one.

   function hello(name1, name2) {...}
   
   hello('Herb')
   // Hello, Herb!
   
   hello('Herb', 'Georgi')
   // Hello, Herb and Georgi!                              

Functions with numbers

arrays, loops

1. Write a function that takes two numbers a and b and multiplies them together.

   function multiply(a, b) { ... }
   
   multiply(3, 4)
   // 12

2. Write a function that takes an array of numbers and adds them all up.

   function sum(arr) { ... }
   
   sum([234, 59253, 12])
   // 59499

3. Write a function that takes an array of numbers and returns the average.

   function average(arr) { ... }
   
   average([5, 7, 12])
   // 8

4. Write a function that takes an array of numbers and returns the largest number.

   function max(arr) { ... }
   
   max([17, 24, 32, 5, 155, 77])
   // 155

Even/odd

1. Write a function named isEven that takes a number and returns true if it is even, false if it is odd.

   function isEven(n) { ... }
   
   isEven(5)
   // false
   isEven(12423578)
   // true

2. Write a function isOdd that takes a number and returns true if the number is odd, false if it is even. Use the isEven function inside isOdd.

3. Write a function named allAreEven that takes an array of numbers and returns true if all the numbers in the array are even.

4. Write a function named someAreEven that takes an array of numbers and returns true if at least one of the numbers in the array are even.

5. Write a function named evenPercentage that takes an array of numbers and returns the percentage of numbers in the array that are even.

Divisibility

1. Write a function that tells if a number is divisible by 3.

   function isDivisibleBy3(n) { ... }
   
   isDivisibleBy3(27) 
   // true
   isDivisibleBy3(25)
   // false

2. Write a function that tells if a number is divisible by 5.

3. Write a function that takes two numbers, n and d, and tells if n is divisible by d.

   function isDivisible(n, d) { ... }
   
   isDivisible(27, 3)
   // true
   isDivisible(25, 5)
   // true
   isDivisible(25, 3)
   // false

4. Refactor isDivisibleBy3 and isDivisibleBy5 so that they use the general isDivisible function internally.

Objects