PHP-and-MySQL/C2/Arithmatic-Operators/English-timed
From Script | Spoken-Tutorial
| Time | Narration |
| 00:00 | Welcome to this tutorial on basic Arithmetic Operators. |
| 00:03 | I'll first go through plus, minus, multiply and divide operations. |
| 00:09 | These are written as plus (+), minus (-), multiply as an asterisk (*) and divide as a forward slash (/). |
| 00:17 | So, I will have 2 variables. |
| 00:20 | I'll create a variable called "$num1" and I'll save that as value equal to 10 and "$num2" is equal to 2. |
| 00:30 | So, these are both integer numbers with no decimal point. |
| 00:34 | Okay, now, say I want to add "num1" and "num2" together. |
| 00:40 | So I echo out the answer of "$num1" added to "$num2". |
| 00:44 | Let's test it out. |
| 00:47 | So, that's "12". 10 and 2, 'num1' and 'num2'; when 10 and 2 are added, the answer is "12". |
| 00:55 | Okay. Now let's try minus. We will just replace the minus symbol there. |
| 01:01 | Refresh and that will be "8". |
| 01:05 | Now let's try multiplication. 10 times 2 is 20 and we've got "20". |
| 01:11 | Next, 10 divided by 2 is just half of 10 which is "5". |
| 01:18 | Now, what we can do is we can add something on the end of this. |
| 01:24 | So, let's say this is divided by 'num2'. |
| 01:27 | So, what I think this operation will do is, it will add "num1" and "num2", so that is 10 and 2 which will give us 12 and then 12 divided by 2. |
| 01:39 | So, 12 divided by 2 should give 6. |
| 01:43 | But actually what this does is, it takes 'num2' and divides it by 'num2' which will give 1 and add 'num1' to that. |
| 01:56 | So, that means, instead of 6 we will get 11. |
| 02:00 | Now, the reason for this is that division operator will always work before addition operator. The same with multiply. |
| 02:10 | Now, to solve this, we should put brackets. |
| 02:16 | The brackets will say - we'll take this operation first, do whatever is in here and then continue to divide by whatever this could be an integer or a variable. |
| 02:29 | So, here what it will do is 'num1' plus 'num2' which is 10 plus 2 which gives us 12 divided by 2 which should give us 6. |
| 02:39 | Let's refresh that and we can see that it worked! |
| 02:43 | So, these are the basic arithmetic operators which are simple to use. |
| 02:48 | If you come across any problems, always verify your calculations with a calculator to make sure they're working. |
| 02:55 | We'll see a few more of these soon. |
| 02:58 | We'll learn about the increment arithmetic operator which increments by 1 but I'll use that a little later. |
| 03:05 | Just practice these and make sure you learn them well. |
| 03:09 | Thanks for watching. This is Arvind, dubbing for the Spoken Tutorial project. |
