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>> SPEAKER 1: Let's write a program that
prompts the user for int, an integer,

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and then does a bit of analysis
on it, telling them whether

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it's positive or negative.

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To do this, let's plan on using the
getint function in the CS50 Library,

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for which I'm going to need
to include cs50.h.

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I'm going to anticipate wanting
to print some things to

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the screen as well.

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So I'm also going to include
standardio.h.

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>> And I'm now going to declare
main as usual.

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int mainvoid, open curly brace, and
preemptively close curly brace.

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I'm going to now prompt
the user for that int.

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Printf, please me an in.

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And I'm now going to get
that int from the user.

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Int, let's call it n, equals getint.

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>> In other words, on the right hand side
of this expression, I'm going to call

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the CS50 function called getint, which
is going to do exactly that.

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It's then going to return that value
from the right hand side of this

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expression to the left hand side of this
expression, ultimately storing

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that value in a variable called n.

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Let's now do a bit of analysis.

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>> For this, I'm going to employ a
condition, or a branch, with if n is,

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say, greater than 0, then I'm
going to do the following.

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Open curly brace and preemptively
close curly brace.

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I'm going to then print out "you picked
a positive integer." /n for

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formatting, close quote, closed
parenthesis, semicolon.

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>> Else, I'm going to want to print
something a little different.

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So else, open curly brace close curly
brace, printf, "you picked a negative

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integer." All right, let's save
and compile this program.

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Make condition zero Enter.

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I'm back at my blinking prompt dot
slash, condition, zero, Enter.

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>> And let's do the simplest
of sanity checks first.

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One as my int, and I indeed
picked a positive integer.

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Let's run this program again with
condition, zero, Enter, "please give

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me an int." Let's try two.

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I indeed picked a positive integer.

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>> Let's go negative this time.

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Dot slash, condition, zero.

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Negative 1 and I picked
a negative integer.

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But I'm not done yet.

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Let's try another corner
case, if you will.

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Let's try zero.

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>> Dot slash, condition, zero,
Enter, and zero.

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And oh boy, I picked
a negative integer.

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But I'm pretty sure zero is defined
as neither positive nor negative.

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So I'm going to have to fix this.

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