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>> SPEAKER 1: Let's take a look at the
simplest of programs and see.

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I've already opened gedit and saved
my file as hello zero.c.

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Let's now recreate it.

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Include standardio.h int main void
open curly brace and, in advance,

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closed curly brace, then an indentation,
printf, quote, unquote

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"hello, world" backslash n close
close parenthesis semicolon.

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>> All right.

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So what are the salient
characteristics of

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this particular program?

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Well, let's start with line one.

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In line one, we have a sharp include
statement followed by standard io.h.

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Well, sharp include simply tells the
compiler go include the contents of

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the following file right
there in my own file.

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What file is that?

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Well, it's a file called
standard io.h.

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And inside of that file are so-called
declarations of functions that we

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might find of interest.

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In this case, printf happens to be the
function that is declared in that

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separate file.

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>> Now in line three, we have
some additional, new

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syntax, int, main, void.

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Well, int refers to the so-called
return type of main,

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what value it returns.

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For the most part, we can turn
a blind eye to this for now.

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But take on faith that main is by
default and implicitly going to

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return, so to speak, a value of zero.

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But more on that another time.

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>> Meanwhile, the name of this
function is, indeed, main.

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And that's the default name for any
program written in C. And then

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finally, inside of the parentheses here,
we have void, which simply says

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that this program takes no
command line arguments.

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But let's take a closer look at
those another day, as well.

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>> Finally, the most interesting line,
of course, is line five.

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And that's where we define the essence
of this program, which is to print to

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the screen, that is, display
hello world.

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Printf is a function.

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And again, that function is declared
in that other file called standard

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io.h that someone else
implemented long ago.

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And printf appears to take one
argument, so to speak.

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Because there is a quoted string, a
sequence of characters, in between

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that pair of parentheses, that implies
that printf, indeed, does take one

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argument, and that argument is going
to influence its behavior.

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>> In this case, it's going to instruct
printf exactly what to

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print on the screen.

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The semicolon, meanwhile, at the end
of this line simply says, that's it

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for this statement.

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I'm all done.

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The fact that on line six we have the
closing curly brace means, indeed,

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this program is complete.

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And there we have it, hello world.

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