# Working with Arrays (1)

Before you get started, make sure you have your text editor and terminal open, and you have navigated to your exercises directory in the terminal. E.g. ```cd ~/ruby-for-beginners/exercises```.

## Exercise 3.1

Create a new, empty file. Save it as `arrays_1-1.rb`. Fill in the following line:

``````numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
``````

So that, when you run your code (run `ruby arrays_1-1.rb`), you get the following output:

``````5
``````

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## Exercise 3.2

Copy your file to a new file: `cp arrays_1-1.rb arrays_1-2.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:

``````99
``````

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## Exercise 3.3

Make a new file `arrays_1-3.rb`, and fill in the following line:

``````numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
p numbers
``````

So that you get the following output:

``````[2, 4, 6, 8, 10]
``````

Read the documentation for the method `select` that you can use on arrays on the Ruby documentation

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## Exercise 3.4

Again, copy your last file to a new file: `cp arrays_1-3.rb arrays_1-4.rb`, then open this new file.

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

``````[10, 8, 6, 4, 2]
``````

The method `select` that you used in the last exercise returns an array. On this array (the return value) you can use another method, by, again, just appending a dot `.` and the method name to it, i.e., to the end of the line.

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

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## Exercise 3.5

Again, copy your last file to a new file: `cp arrays_1-4.rb arrays_1-5.rb`, then open this new file.

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

``````[10, 8, 4, 2]
``````

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

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