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Arithmetic Operators
5:43An operator is anything that takes one or more values and returns another value. We'll cover a number of different ways to add, subtract, multiply and divide values in PHP.
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So let's talk about operators.
0:00
An operator is anything that takes one or
more values and returns another value.
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When we assign a value using an equal
sign that was an assignment operator.
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When we added numbers using a plus symbol,
that's an arithmetic operator.
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When we subtracted numbers using the minus
symbol that's also an arithmetic operator.
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Besides the addition and
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subtraction operators, there are a few
more operators we're going to use.
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So let's define a few variables and get
started using some arithmetic operators.
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I'll start by defining
a few more integers.
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I'll add $a equals five,
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and then I'll add another
one $b equals ten.
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We've got two different variables
that contain different values.
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We already use the plus sign for
addition and minus for
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subtraction, so
let's try a few more operators.
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Let's display the product using
the multiplication operator,
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which is the asterisk.
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var_dump $a times $b.
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Let's add one more here.
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I'll do the quotient.
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The quotient uses the division operator,
which is the forward slash.
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We'll use, var_dump $a divided by $b.
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Now let's run our script.
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We see that $a multiplied by
$b gives us the integer 50.
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5 multiplied by 10 equals 50.
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We also see that $a divided
by $b gives us a float, 0.5.
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5 divided by 10 equals 0.5.
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So we can see that even though the
variables in these equations are integers,
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the results will be returned in
whichever variable type is needed.
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The next operators that I wanna
talk about are the incrementing and
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decrementing operators.
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These are often used within a loop.
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I'll be covering loops in a later course,
but for
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now, let's just say we want
to add one to our variable a.
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We could do $a equals $a plus 1,
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and then do a var_dump.
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Now let's run our script.
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And we see that $a equals the integer 6.
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5 plus 1 equals 6.
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We can also do this with
PHP's incrementing operator.
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I'll duplicate this var_dump line,
and then I'll do $a plus plus.
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Now let's run our script again.
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$a now equals 7.
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Using plus plus is
the same as using plus 1.
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Six plus one equals seven.
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The opposite of that is
a decrementing operator.
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If I duplicate the var dump once
more I can add a minus minus,
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now when I run the script,
$a equals 6 again.
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7 minus 1 equals 6.
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We can use these operators before or
after the variable.
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The end result is the same, but
they work slightly different.
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If we put the assignment within
a var_dump, you can see what's happening.
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Now when we run our script
the second from the last equals 6,
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but the next dump evaluates as 5.
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If I add the operator before
the variable it will first subtract and
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then return the value.
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Let's do minus minus $a and save the file.
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So the last two dumps both equal four.
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There's one last set of operators that
we should talk about before moving on.
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If we want to add or subtract more than
one at a time, we do have another option.
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There are combined operators that combine
assignment with arithmetic operators.
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For example, if we want to
increase the value of $a by five,
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we could do $a equals $a plus 5.
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Then we var_dump our $a.
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Now we can run the script, and
we can see that $a now equals 9.
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4 plus 5 equals 9.
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We can also combine those operators for
a shorter version.
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Let's do.
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$a plus equals five.
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Now when we run our script,
we can see that $a equals fourteen.
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9 plus 5 equals 14.
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These combined operators work with
any of their arithmetic operators,
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addition, subtraction,
multiplication and division.
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That was a lot of numbers and
a lot of different operators.
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Feel free to re-watch the video to
review anything you may have missed.
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Most importantly, make sure you try
these operations out for yourself.
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You'll understand and
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remember the coding concepts much more,
if you've written the code yourself.
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