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- 2x 2x
- 1.75x 1.75x
- 1.5x 1.5x
- 1.25x 1.25x
- 1.1x 1.1x
- 1x 1x
- 0.75x 0.75x
- 0.5x 0.5x
Utilize iterative coding to catch errors and bugs early on.
Iterative coding is a process where you code a small piece of your project and then test it, then code the next piece and test it, so on and so forth.
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Hi there,
let's chat about iterative coding.
0:00
You may have already been using
this strategy and not even know it.
0:04
[SOUND] Iterative coding always
reminds me of the carpentry mantra,
0:08
measure twice, cut once.
0:13
[SOUND] If you were to tackle
a project without testing any code,
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it would be like cutting wood for
a chair without measuring.
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The chair probably wouldn't turn out
like the way you wanted it to and
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now you have to spend more time
and materials to make it right.
0:28
It's the same for a coding project.
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You would probably end up with bugs in
your code, and trying to find and fix them
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would be more difficult and frustrating
than if you had measured first.
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When writing out your code,
stop every so often and
0:46
test your code by printing
out elements to the console.
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This is your measure twice.
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You'll catch more bugs this way and
end up saving a lot of time and
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headaches in the long run.
0:59
Let me walk you through a small code
challenge to model how this process works.
1:01
In this challenge,
1:07
we need to replace a character in
a word with a different character.
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We're given the word piccolo and
the index is randomly chosen.
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And the character to replace
with is the letter t.
1:20
We need to create the logic inside of
the given function, replace character.
1:24
A good first step is to print out
the random index we are given so
1:30
we can check our work as we go and make
sure we're changing the correct letter.
1:35
Let's also print out that letter
in piccolo at that given index.
1:46
We can do that by using
the index on the string itself.
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Great, don't forget to call
the functions so it will run.
2:00
And lets run the file to see what
gets printed to the console.
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I got 5 and l.
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Since this is randomized,
you may have gotten something different.
2:35
If I run the file again,
I get a different result, nice.
2:39
Count through the word piccolo to see if
you are accessing the right character.
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Numbering always starts at 0 so
with our index of 6,
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Zero, one, two, three, four,
five, six, we get the letter o,
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which is what was printed to the console.
3:03
Now let's get into how to change
this letter into the letter t.
3:08
Strings are immutable.
3:13
So if I try to change
the letter like this,
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When I run the file,
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I get an error.
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I will need to change the string
into something I can change.
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I'm going to break the string into a list,
as it's called in Python or
3:50
an array in other languages.
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I can do this by calling list
with the string as the parameter.
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Let's print out our split string to make
sure it's breaking up the string into
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individual characters like we want.
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Sweet, okay, so now we need to change
the right character into the letter t.
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Luckily, even though the string is now
a list, the index numbers stay the same.
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So let's try what we did earlier but
with our list.
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Again, print out your list to
make sure the changes occurred.
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Great, our changes worked.
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The last thing I need to do is
put the word back together again.
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We can do this by using join.
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The first part is how we want to join,
which is to have no spaces at all.
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Then we call join and
pass it our updated list.
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Then you guessed it,
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let's print out our word to
see it all put together again.
5:52
Nice work.
6:07
Now that we have created the logic,
you can go back and
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remove the other print statements so they
don't take up your console space anymore.
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And you're all done.
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You've completed the challenge.
6:29
This process can seem tedious at times,
but printing out and checking your code
6:31
as you go can help you find errors in your
code a lot faster than writing out all
6:37
of the logic and then working backwards
to figure out where something went wrong.
6:42
It can also help you to better
understand how language works.
6:47
When in doubt, print it out.
6:51
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