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Arithmetic Operators5:43 with Alena Holligan
An 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.
So let's talk about operators. 0:00 An operator is anything that takes one or more values and returns another value. 0:02 When we assign a value using an equal sign that was an assignment operator. 0:08 When we added numbers using a plus symbol, that's an arithmetic operator. 0:13 When we subtracted numbers using the minus symbol that's also an arithmetic operator. 0:18 Besides the addition and 0:24 subtraction operators, there are a few more operators we're going to use. 0:26 So let's define a few variables and get started using some arithmetic operators. 0:30 I'll start by defining a few more integers. 0:36 I'll add A equals five, 0:39 and then I'll add another one B equals ten. 0:42 We've got two different variables that contain different values. 0:50 We already use the plus sign for addition and minus for 0:53 subtraction, so let's try a few more operators. 0:56 Let's display the product using the multiplication operator, 1:00 which is the asterisk. 1:03 Var_dump A times B. 1:04 Let's add one more here. 1:13 I'll do the quotient. 1:14 The quotient uses the division operator, which is the forward slash. 1:15 We'll use, var dump A divided by B. 1:20 Now let's run our script. 1:26 We see that a multiplied by B gives us the integer 50. 1:27 5 multiplied by 10 equals 50. 1:33 We also see that A divided by B gives us a float, 0.5. 1:36 5 divided by 10 equals 0.5. 1:43 So we can see that even though the variables in these equations are integers, 1:47 the results will be returned in whichever variable type is needed. 1:52 The next operators that I wanna talk about are the incrementing and 1:55 decrementing operators. 1:59 These are often used within a loop. 2:02 I'll be covering loops in a later course, but for 2:03 now, let's just say we want to add one to our variable a. 2:06 We could do a equals a plus 1, 2:11 and then do a var-dump. 2:17 Now let's run our script. 2:23 And we see that a equals the integer 6. 2:24 5 plus 1 equals 6. 2:29 We can also do this with PHP's incrementing operator. 2:32 I'll duplicate this var dump line, and then I'll do A plus plus. 2:37 Now let's run our script again. 2:47 A now equals 7. 2:50 Using plus plus is the same as using plus 1. 2:51 Six plus one equals seven. 2:56 The opposite of that is a decrementing operator. 2:59 If I duplicate the var dump once more I can add a minus minus, 3:02 now when I run the script, A equals 6 again. 3:12 7 minus 1 equals 6. 3:17 We can use these operators before or after the variable. 3:20 The end result is the same, but they work slightly different. 3:24 If we put the assignment within a var_dump, you can see what's happening. 3:28 Now when we run our script the second from the last equals 6, 3:45 but the next dump evaluates as 5. 3:50 If I add the operator before the variable it will first subtract and 3:54 then return the value. 3:58 Let's do minus minus A and save the file. 4:01 So the last two dumps both equal four. 4:08 There's one last set of operators that we should talk about before moving on. 4:12 If we want to add or subtract more than one at a time, we do have another option. 4:16 There are combined operators that combine assignment with arithmetic operators. 4:22 For example, if we want to increase the value of A by five, 4:27 we could do a equals a plus 5. 4:32 Then we var_dump our a. 4:38 Now we can run the script, and we can see that a now equals 9. 4:44 4 plus 5 equals 9. 4:49 We can also combine those operators for a shorter version. 4:54 Let's do. 4:57 A plus equals five. 5:01 Now when we run our script, we can see that a equals fourteen. 5:06 9 plus 5 equals 14. 5:11 These combined operators work with any of their arithmetic operators, 5:15 addition subtraction, multiplication and division. 5:19 That was a lot of numbers and a lot of different operators. 5:24 Feel free to re-watch the video to review anything you may have missed. 5:27 Most importantly, make sure you try these operations out for yourself. 5:32 You'll understand and 5:37 remember the coding concepts much more, if you've written the code yourself. 5:38
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