Arithmetic Operators

Quick reference

• 00:05 In the last video, we talked about data types.
• 00:07 In this video I want to talk about math.
• 00:09 Specifically arithmetic operators.
• 00:11 In programing languages, there are a lot of different operators, there's arithmetic
• 00:15 operators, there's assignment operators, comparison operators,
• 00:18 increment operators, logic operators, string operators, and on and on.
• 00:21 We're gonna talk about all those other things in coming videos, but in this one,
• 00:25 we're going to start with arithmetic operators, and that's just math right?
• 00:29 One of our data types, actually 2 of our data types were integers and floats.
• 00:33 And integers are numbers and whenever you want to do something with numbers you're
• 00:37 going to use an arithmetic operator.
• 00:41 Let's create a variable called number.
• 00:43 Set it equal to 41, actually let's call this number 1.
• 00:49 All right? And let's create another one called number
• 00:51 two and set this equal to four.
• 00:55 To do math, it's just like you think it is.
• 00:58 You use plus, minus, multiplication, the little star guy, division, forward slash.
• 01:05 For exponents, 2 to the 4th power,
• 01:07 something like that, double multiplication.
• 01:11 And finally there is the modulus and we'll talk about the modulus in just a minute.
• 01:15 It's pretty important but a modulus is basically just a remainder
• 01:19 if you took 10 divided by 3, 3 goes into 10 three times right?
• 01:23 3 times 3 is nine with 1 remainder,
• 01:26 remember your division in like fourth grade?
• 01:28 Math class when you're a student, 10 divided by 3 is 3 remainder 1.
• 01:32 So this modulus would return one.
• 01:35 Let's spend just a quick minute or two talking about each of these things.
• 01:39 Now to do math in PHP it's pretty simple.
• 01:41 You just go, let's echo out number1 + number2.
• 01:48 If we save this come back here and click Reload, we get 45 which is 41 + 4.
• 01:53 Let's go 5 and 1, here we go.
• 01:58 Change that around, save it, hit reload, boom, 6.
• 02:00 So that's simple addition.
• 02:02 To do subtraction 5- 1.
• 02:07 4.
• 02:08 Multiplication is just the way you would think it is.
• 02:11 5 times 1 is 5.
• 02:14 Division 5 divided by 1.
• 02:18 It's gonna be 5.
• 02:19 And let's go exponents.
• 02:20 So this would be 5 to the first power.
• 02:23 Which is 5 right.
• 02:24 Let's change this to 2.
• 02:26 So now that's gonna be 5 to the second power which should be 25 right.
• 02:31 Now, I actually got an error.
• 02:32 This is interesting.
• 02:33 This exponent operator was changed in a later version of PHP.
• 02:37 It looks like we're running an old version of PHP on our C9 development environment.
• 02:41 So, to use exponents on this thing.
• 02:44 We need to change it a little bit and uses pow cuz we are raising it to the power.
• 02:48 So we say things as number 1, number 2,
• 02:52 that's five to the second power which is 25.
• 02:57 Same basic thing say the difference and finally the modulus, so
• 03:01 let's go number1 modulus
• 03:07 number 2 or saying what's 5 divided by 2?
• 03:11 2 goes into 5 2 times with 1 leftover.
• 03:14 So this should return 1.
• 03:15 So if we save this, hit reload.
• 03:17 Boom, it's 1.
• 03:18 Now let's change this to 10.
• 03:20 What is 10 divided by 2?
• 03:23 It's 5 with 0 remainder.
• 03:25 Right? Cuz 2 goes into 10 five times.
• 03:28 So, we click reload, 0.
• 03:29 So, that's the modulus, we'll play with that a little bit later on.
• 03:32 That's pretty much it.
• 03:33 That's arithmetic operators.
• 03:34 Math is very simple on most computer programming languages.
• 03:38 PHP, it's very simple as we've just seen.
• 03:41 And in the next video we'll talk about assignment operators.

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