All language subtitles for 16. Increment and Decrement Expressions

Now so far what we have seen are all operators that exist in normal mathematics.
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But here are some that only exist in programming.
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So take a look at this expression.
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We create a variable called x and we set it equal to 5.
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Then we change the value of x to the previous value,
which is 5, plus 1.
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So x now equals 6.
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Now we've seen this and we've been using this in our previous code.
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So this should be familiar to you already.
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But in most programming languages, instead of writing out x = x + 1, you can simply write
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x++, and, in exactly the same way, x now gets incremented by 1 and is now equal to 6. So x++
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is the equivalent of saying x = x + 1, and this is called the increment expression.
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Now you can go the other way as well.
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You can write x--,
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and this is equivalent to x = x - 1.
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So the previous value of x, 5, minus 1, so x now equals 4.
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And this is called the decrement expression.
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Now you might have heard of the programming language C and C++, and this is kind of like a programmer's
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idea of a good joke, even though nobody else thinks it's funny.
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But essentially C++ was meant to be an increment on the C programming language.
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So it's kind of like C plus one, a little bit better than C. Remember that with ++ and --,
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you're only ever changing the value by one.
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Now if you ever want to increase the value of x by more than one, then you can use the +=, and
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this is equivalent to saying x = x + 2.
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And so x now equals 7. In the same way,
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you can also use += to increase by the value of another variable.
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So in this case x = x + y, which is equal to 8.
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And this also works with -=, *=, /=,
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and it's a handy shorter way of doing exactly that.
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So, in the next lesson,
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I have a brief quiz for you to see if all of this stuck
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and if it makes sense.
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So head over there and see if you can complete the multiple choice question and I'll see you on the
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next module.