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1. Go through the ruby String documentation and look for a method or function that prepends or combine one string to another string. Using said method prepend the string "Learning " to the string "Ruby".

2. Go through the ruby String documentation and look for a method or function that remove characters from a string. Using said method, it turns the string "Learning Ruby" into the string "Lrnng Rby".

3. There is a ruby String method that allows to justify a string, padding it with another string. Find said method and use it on the string "Ruby" together with "<3" so that you get the following string result:

"Ruby<3<3<3"

4. Create a ruby application called exercise_04.rb. Fill it in with the following lines:

numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
# your code goes here...

So that, when you run your code, e.g., ruby exercise_04.rb, you get the following output

5

5. Copy exercise_04.rb to exercise_05.rb, then open this new file. Add another line before the line that you just added, so that, when you run your code you get the following output:

55

6. Create a new ruby file called exercise_06.rb, and fill in the following line:

numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
# your code goes here...
puts numbers.inspect

So that you get the following output:

[2, 4, 6, 8, 10]

Tip: Consult the ruby Array documentation for the correct method or function to use.

7. Again, copy the finished exercise_06.rb to exercise_07.rb.

Now change the code so that you get the following output:

[10, 8, 6, 4, 2]

Tip: Consult the ruby Array documentation for the correct method or function to use.

Note: The method select that you used in the last exercise returns an array. On this array (the returned value) you can use another method by appending another dot ., and the method that would produce the output [10, 8, 6, 4, 2].

Note: There is another method that reverses the order of the array. You can find it by googling for “ruby array reverse”.

8. Again, copy the finished exercise_07.rb, then change your code so that you get the following output:

[10, 8, 4, 2]

Tip: Consult the ruby Array documentation for the correct method or function to use.

Bonus: Find at least three different solutions for this last change.

9. Create a new file called exercise_09.rb, and fill the following lines:

dictionary = { :one => "ichi", :two => "ni", :three => "san" }
# your code goes here...

So that it prints out

ni

10. Create a new file called exercise_10.rb and fill in the following line:

dictionary = { :one => "ichi", :two => "ni", :three => "san" }
# your code goes here...
puts dictionary[:four]

So that it prints out

shi