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All right. So in this lesson, we're going to be debugging our leap year

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coding exercise. You've done this coding exercise before, you wrote this code

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which checks to see if a year is a leap year.

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It prints leap year if it's true, and not leap year

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if it's not a leap year.

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All you have to do is to fix this code.

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So use what you learned about debugging and try to fix this coding exercise.

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So pause the video now.

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Okay.

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All right. So first off,

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let's go ahead and just run our code and see if it works.

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And then we're going to enter a known leap year.

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So a quick Google away lets see when is a leap year.

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Well, 2020 seems to be a leap year. So let's try that.

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Let's check 2020. And we get an error.

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So errors are good. They're much easier to fix than the Programming problems

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which have no errors.

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And it tells us that there's a problem on line three and it's a type error,

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not all arguments converted during string formatting.

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What does that mean? Well, what's a type error anyways?

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A type error is when you're trying to do something with the wrong data type. In

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our case, it's pointing at line three. So if we take a look at line three,

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what's happening here?

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Well, currently we're trying to take the year that the user inputted, so 2020, and

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divide it by four to see if the remainder is equal to zero.

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Now, this is a little bit harder to solve than the previous one.

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But what you should realize is that it's pointing towards a type error,

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so what data types have we got going on? Well,

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if we go ahead and print the type of our year,

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then you can see that it's of class string.

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But if we print the type of this 4 that

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we're trying to divide it by, that is of class int.

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So this is the problem. These two types are not matched.

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So when you try to divide a string by an integer,

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this is what ends up giving you this problem.

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So why is this a string when we entered a number?

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Well it's because the input function, remember, gives the user a prompt and then

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takes whatever they type in the console and turns it into a string.

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So in order to turn this into an int which is what we want,

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we have to wrap it around a set of parentheses and then type

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convert it into an integer. And now when we run it again,

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we can see that it actually works. And we're happy that we fixed our code.

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Once you're done with this challenge,

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head over to the next one and complete the final debugging exercise.