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C Programming Tutorial - 15 - Simple Array Program

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    What's up, everyone? Welcome to
    your—uh, it's like, 15th or somethin'—
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    tutorial on arrays. And the
    last one was on arrays,
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    but I promised that I would build
    an application to show you guys
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    why arrays are actually useful,
    so that's what I'm going to do now.
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    So, all you have to do is follow along,
    and open your mind, and... just learn.
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    The first thing that I'm gonna do
    is build an array, just like last time.
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    Let's put five elements in it.
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    And let's go ahead and fill this
    array with some kind of elements.
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    Let's say, the ages of...
    my brothers and sisters.
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    And... I don't have five
    brothers and sisters, so...
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    We'll go 21 for me, 18, uh... let's say,
    pretend I had one that was 47.
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    Another one that was 21.
    That's my twin, named Mucky.
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    And another baby sister named 4.
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    So that's one, two, three, four, five.
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    So remember, the position
    number for each of these
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    is zero, one, two, three, four.
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    And you could have these any
    numbers you want; it doesn't matter.
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    The next thing I'm gonna do is go
    ahead and build a counting variable.
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    And in case you guys don't know—and
    by "case," I mean you guys don't know,
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    because I didn't tell you yet.
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    This application is just gonna add
    up all the numbers in the array for us.
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    So, we're gonna be building a
    "for" loop later with a counting variable,
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    so that's why I need that.
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    And the last thing I need is a variable
    to keep the sum of the total,
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    or, pretty much, the sum or
    the total; however you say it.
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    So now that we got our
    array in two variables,
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    one for the counting variable
    and one to keep the sum,
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    let's go ahead and build a for loop.
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    Now, our first condition is,
    I need to start at zero.
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    And this is because the
    first position number of this,
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    is gonna be zero,
    and it's gonna go to four.
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    So let's go ahead and add our
    next condition, the maximum.
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    "i" is less than five.
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    And we have less than five
    and not equal to five because
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    it's always gonna be
    less than five, which is four.
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    If we put less than or equal to,
    it's gonna try to get that fifth number,
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    and zero, one, two, three, four—
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    there is no five; it always
    goes from zero to four.
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    Not always, but in this case.
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    And now, let's go ahead.
    "i++."
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    Since we wanna just loop
    it through one at a time.
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    Don't get anything fancy.
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    So, let me go ahead and—
    Come on. Format.
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    Whatever. Do this the hard way.
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    So... Wow, this is a pain
    in the butt right now.
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    So, next, we have to write
    what we want our program to do.
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    So let's go ahead and take the total.
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    And right now, the total is zero.
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    So what we wanna
    add to it is, loop through.
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    Let me—let me type. I can't, uh,
    think and type at the same time.
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    And that is our program right there.
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    So, what this is gonna do
    is it's gonna go, all right.
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    You now have the variable i=0.
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    So we're gonna take the zeroth-
    position number, which is 21,
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    and add it to the total.
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    Next, we're gonna loop through
    when i equals one.
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    So when i equals one, we're gonna
    take 18, and add it to the total.
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    So whatever 18 +21 is,
    and that's gonna be the total.
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    Next, it's just gonna
    loop through all of that
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    until we get through
    all of these, right here.
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    So, just to output something on the screen
    to prove to you guys that it worked.
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    Go ahead and printf.
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    Did I get that right? Yep.
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    Uh... let's go ahead... how
    are we gonna format this?
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    "The total number is..." And I know
    I'm spelling everything wrong.
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    I know I spelled "number" wrong, so don't
    comment a thousand times tellin' me.
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    "%d." Let's go ahead
    and add a new line.
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    No, we won't. Just kiddin', sucker.
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    "total." So, let me just run this real
    quick, and then I'll explain to you guys
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    exactly what it did one last time, so
    you guys aren't totally lost in the dark.
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    So it's gonna loop through, and it's
    gonna say the total number is—
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    again, "numebr," is 111.
    That's exactly what we wanted.
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    Now, one last time, let me explain
    to you guys how, exactly, this worked.
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    The first thing we did is build
    an array with five elements in it.
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    Now, those arrays are listed
    zero through four,
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    just 'cause your computer's weird.
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    Next thing we do is go to
    a counting variable,
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    and build a variable to hold
    the sum of our numbers.
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    We started with a zero-with
    element in our array,
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    and looped through until
    we got to number four.
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    As you can say, "i" is less
    than 5, which is 4.
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    And this is just the
    loop-through one at a time.
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    We then took each of those elements
    and added it into the total variable,
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    so it looped through each time,
    and each time it did,
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    it added a new number
    to the variable total.
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    And at the end—you guys
    should know this by now.
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    What we did is simply
    print out that number.
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    So again, that is one way that you
    can use a loop to loop through
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    the elements in your array,
    and this is just to show you guys
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    that array isn't totally useless, and
    you can actually use it for something.
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    So, this is a very simple program.
    I encourage you guys to build this.
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    Again, I wanna thank
    you guys for watching.
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    Don't forget to subscribe to my channel.
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    Again, thank you, and make sure
    to check out my next tutorial.
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C Programming Tutorial - 15 - Simple Array Program
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Video Language:
English
Duration:
05:32

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