How to make a method take one or two arguments? [duplicate]

Question

This question already has answers here:

Should repeat a number of times (3 answers)

Closed 9 years ago.

I am working on an exercise to make the following tests pass:

  describe "repeat" do
    it "should repeat" do
      repeat("hello").should == "hello hello"
    end

    # Wait a second! How can you make the "repeat" method
    # take one *or* two arguments?
    #
    # Hint: *default values*
    it "should repeat a number of times" do
      repeat("hello", 3).should == "hello hello hello"
    end
  end

I am not understanding this part for some reason.

When I use this:

def repeat(z)
    return z + " " + z
end

The first part of the test passes but the second one fails.

Then when I try this:

def repeat(z, 2)
    return z * 2
end

I get an error the quits the test/rake.

And then when I try:

f = 2
def repeat(z, f)
    return z * f
end

The test won't pass and I get this message:

wrong number of arguments (1 for 2)

I have no idea what is happening here, can someone explain how this works?

Answer 1

You can define the function like following:

def repeat(z, y=2)
    return z * y
end

So now, repeat("hello") will result: hellohello and repeat("hello", 3) will return hellohellohello

Answer 2

It seems you're doing the Simon Says exercise.

The purpose of this exercise is to teach you how to take one or multiple arguments, using the default values.

Whenever you assign a default value using the "x = default value", it will be used. If the method was called with a different value, it would be used.

In the example below, the default value of number is 2.

    def repeat(word, number = 2)
        ([word] * number).join(" ")
    end

Using the above, we can call repeat("Hello", 3) and it would result with "hello hello hello"

If we call repeat("Hello"), by default it will return "hello hello"

Hope this helps!!!