Learn to Code In 5 Minutes A Day: Lesson 11

Lesson 10 Solution: Roman Numeral 4

Did you get a solution that looks something like this?

func roman(number int) string {
	result := ""
	if number == 4 {
		return "IV"
	}
	for i := 0; i < number; i++ {
		result += "I"
	}
	return result
}

or did you get a solution that looks like this?

package main

func roman(number int) string {
	result := ""
	if number == 4 {
		result = "IV"
		number = number - 4
	}
	for i := 0; i < number; i++ {
		result += "I"
	}
	return result
}

Either way works:

% go test
PASS
ok      hello   0.222s

As an experienced developer, my spider-sense makes me lean towards the second option, just because I can see that in the future, I might need to start adding on “I” to the end of things. For example, 6 = VI, 7 = VII, 8 = VII. I don’t want to get ahead of myself until I write the tests. But this is one of those situations where experience nudges me in a certain direction.

So I’m going to suggest you update your code to look like this:

package main

func roman(number int) string {
	result := ""
	if number == 4 {
		result = "IV"
		number = number - 4
	}
	for i := 0; i < number; i++ {
		result += "I"
	}
	return result
}

As always, if you don’t understand everything we did to this point, back up and solve it again and again until you do understand it.

Lesson 11: 5/V

Next up, let’s write a unit test for 5/V. Can you do this on your own without reading ahead? And can you write the solution to it? Remember, write the test, run the test, see it fail, then write the code that makes the test pass.

Next Lesson

• learn to code
• lesson 11
• golang