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Very often I've asked you in the quizzes

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especially to play computer.

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And the reason is because this skill of pretending to be a computer reading

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through your code and imagining what you going to do each time is really,

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really useful, especially when you're debugging.

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So let's comment out the previous block and try the next block.

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Take a look at this code.

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It takes an input

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in the form of an integer and it ask the user for their year of birth.

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And then it uses an if statement to check if they were born between 1980 and

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1994, in which case they're classified as a millennial.

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But if there were born later than 1994, then they're classified as a Gen Z.

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So depending on which country you're from,

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there's different classifications for your particular generation.

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This is just the typical words that you hear on the internet.

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You're a millennial, you're a Gen Z, you're a baby boomer,

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and this comes from a lot of the history of the US. But nonetheless,

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I want you to run the code and I want you to see what happens when I put in

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1994. Absolutely nothing,

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so we have our bug right there. Run through the code line-by-line and evaluate

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each statement. For example, if year is equal to 1990,

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will line 77 evaluate to true or to false?

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What if year is equal to 1994?

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Look at each line of code and follow the logic and check what it will evaluate

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to.

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So I want you to play computer and figure out what is the problem,

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and then go ahead and fix the bug. Pause the video now.

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All right. So

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let's pretend that we got 1994 as the input.

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So now I'm the computer

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and I know that this year is equal to 1994.

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Now with this year being equal to 1994,

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I go into this if statement so is 1994,

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greater than 1980? Yes it is.

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So this actually becomes true.

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Now I have to check the second condition and it also has to be true for this if

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block to be triggered. So is 1994,

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less than 1994? No, it's not.

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It's actually less than equal to 1994,

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or it's equal to 1994. So in this case,

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this condition becomes false.

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And we know that if we try to combine a true and a false then it actually just

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becomes a false.

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So this gets skipped.

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Now, next, we look at the next statement, right?

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If 1994 is greater than 1994,

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well, that's also not true. It be greater or equal to,

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or it could just be equal to.

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So this condition is also false.

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So that means it's also going to skip this next line and there's no more lines

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of code left, which is why the computer doesn't print anything.

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So let's restore our code to before we started playing computer

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and we can identify that this problem occurs because there is no bucket that

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actually catches the 1994.

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We could simply fix this code by changing one of these conditions to be greater

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than or equal to either here or here.

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And that means that the year 1994 is not skipped over in our conditions.

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And when we hit run, it will actually tell us that we are in fact,

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a Gen Z.