Defining methods

Exercise 5.1

Write a method greet that takes a name, prepends "Hello ", and appends an exclamation mark "!":

  1. def greet(name)
  2.   # your code goes here
  3. end
  5. puts greet("Ada")

This should print out Hello Ada!.

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Exercise 5.2

Once you’ve implemented the method this should print out: Hello Ada!.

Now change your method so that instead of always using "Hello " it picks a random string from the array ["Hello", "Hi", "Ohai", "ZOMG"].

Every time you run the program it should print out either "Hello Ada!", "Hi Ada!", "Ohai Ada!", or "ZOMG Ada!".

The method shuffle on arrays does, well, shuffle the array :) That means it changes the order of the elements in the array in a random way.

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Exercise 5.3

Write a method that converts a distance (a number) from miles to kilometers:

  1. def miles_to_kilometers(miles)
  2.   # your code goes here
  3. end
  5. puts miles_to_kilometers(25)

This should print out:

  1. 40.2336

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Exercise 5.4

Write a method leap_year? that takes a year (a number), and calculates if it is a leap year.

  1. def leap_year?(year)
  2.   # your code goes here
  3. end
  5. p leap_year?(2012)
  6. p leap_year?(2015)

This should print out:

  1. true
  2. false

Hint: The operator % returns the rest of a division. E.g. 14 % 3 returns 2.

Bonus: Also make it so that the method returns true for the year 2000 and false for 1900 … because that’s really the definition of leap years.

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