Difference between revisions of "PHP-and-MySQL/C2/If-Statement/English-timed"
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Sandhya.np14 (Talk | contribs) |
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| − | |Okay, here is a brief about the 'IF' statement. It takes a condition. | + | |Okay, here is a brief about the 'IF' statement. It takes a '''condition'''. |
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| − | |Notice I am using a double 'equal to' sign here. This is the comparison operator. | + | |Notice I am using a double 'equal to' sign here. This is the comparison '''operator'''. |
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| − | |When we're using variables, | + | |When we're using variables, we want to compare we use 'double equal to'. |
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| − | |If it's 'Not True', we'll say 'else'. | + | |If it's 'Not True', we'll say '''else'''. |
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| − | |For example, if 1 equals 1 we say '''echo''' 'True'. | + | |For example, '''if 1 equals 1''' we say '''echo''' 'True'. |
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| − | |Say, the password is "abc". | + | |Say, the '''$password''' is "abc". |
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| − | |if password, remember double equals | + | |if '''password''', remember double equals "def" |
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| − | |and I'll say 'Access granted'. | + | |and I'll say '''Access granted'''. |
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| − | |So, if it doesn't equal 'def', I'll say 'Access denied'. | + | |So, if it doesn't equal 'def', I'll say '''Access denied'''. |
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| − | |If this equals 'def', we're going to say 'Access granted' else 'Access denied'. | + | |If this equals 'def', we're going to say '''Access granted''' else '''Access denied'''. |
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| − | |'Access denied'. This is because the passwords do not match. | + | |'''Access denied'''. This is because the passwords do not match. |
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| − | |Change this to 'def' and we'll get 'Access granted'. | + | |Change this to 'def' and we'll get '''Access granted'''. |
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| − | | | + | |'''$access''' equals "Allowed". |
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| − | |It says an unexpected T_else on line 8. | + | |It says: an unexpected T_else on line 8. |
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| − | |We '''refresh''' this and Access is granted. | + | |We '''refresh''' this and '''Access is granted'''. |
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| − | |Now I've set a new variable, access to be allowed. | + | |Now I've set a new variable, '''access''' to be '''allowed'''. |
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Revision as of 21:28, 18 May 2015
| Time | Narration |
| 00:00 | Welcome to this basic php Spoken Tutorial. Here we will discuss the IF statement. |
| 00:06 | If you have written code before, you would have come across the 'IF' statement. |
| 00:11 | It's not much different in php. I'll execute one shortly and show you. |
| 00:16 | So, let us start. |
| 00:18 | Okay, here is a brief about the 'IF' statement. It takes a condition. |
| 00:23 | If the condition is True, it executes one path of code. |
| 00:28 | If it is False, it will execute another path of code. |
| 00:32 | For example - this is the structure. |
| 00:36 | If - inside the bracket is the condition to know whether 1 equals 1. |
| 00:41 | Notice I am using a double 'equal to' sign here. This is the comparison operator. |
| 00:47 | In another tutorial we're going to learn about operators. |
| 00:50 | It reads as 'is equal to' though it is not the same as 'equals'. |
| 00:56 | When we're using variables, we want to compare we use 'double equal to'. |
| 01:02 | If you are going for the 'True' path, you can use two curly brackets. |
| 01:06 | We're going to open one here. |
| 01:08 | Our code will go in between the brackets. |
| 01:12 | If it's 'Not True', we'll say else. |
| 01:15 | The same structure - so, two curly brackets. |
| 01:17 | For example, if 1 equals 1 we say echo 'True'. |
| 01:23 | If 1 is not equal 1, what we should get when we run our file is False. |
| 01:30 | Since 1 is equal to 1, what we get when we run our file is True. |
| 01:36 | Let us change this. If 1 equals 2, which it doesn't, then we'll get False. |
| 01:42 | So, we would have already created a simple program to tell us if one number equals another. |
| 01:49 | This is quite a silly application for a program. |
| 01:52 | So, I will just add something more. I'll create a little program for a password access. |
| 01:58 | We are going to store the password in a variable here. |
| 02:03 | Say, the $password is "abc". |
| 02:05 | I am going to incorporate a variable into my IF function by saying: |
| 02:11 | if password, remember double equals "def" |
| 02:15 | and I'll say Access granted. |
| 02:21 | Sorry, I made a mistake. 'def' is the password we want to ask the user for. 'abc' is the password I'm inputting to the system. |
| 02:32 | So, if it doesn't equal 'def', I'll say Access denied. |
| 02:39 | The password that I've inputted is 'abc'. |
| 02:42 | We're going to compare the password to 'def' which is the stored password. |
| 02:50 | If this equals 'def', we're going to say Access granted else Access denied. |
| 02:57 | Let's try this. |
| 03:00 | Access denied. This is because the passwords do not match. |
| 03:05 | On this basis, you can see here that I've incorporated a variable. |
| 03:10 | Change this to 'def' and we'll get Access granted. |
| 03:18 | Because I have one line of code here and another one line of code here. |
| 03:22 | I can get rid of these curly brackets. |
| 03:25 | To me, that looks a lot neater. |
| 03:29 | Please note - there is no point in adding curly brackets if you have only one line of code for simple IF statements like these. |
| 03:37 | If you're going to have a line after line here, you'll need the curly brackets. |
| 03:42 | For example, let's set a new variable here. |
| 03:46 | $access equals "Allowed". |
| 03:52 | That's just basically another line of code. |
| 03:57 | But when I try and run this, we get an error. |
| 04:02 | It says: an unexpected T_else on line 8. |
| 04:08 | Let's find line 8. It's here. The line before it is causing a problem. |
| 04:13 | Which is why we need to add our curly brackets back in to cater for two or more lines of code. |
| 04:22 | We refresh this and Access is granted. |
| 04:25 | Now I've set a new variable, access to be allowed. |
| 04:29 | This won't be of much help. |
| 04:32 | But I was just giving you an example. |
| 04:35 | You can see this is still a single line and these are double lines and you can't mix them up. |
| 04:40 | OK, so I've created a variable. I've incorporated it into an 'IF' statement. Hope this was useful. |
| 04:46 | This brings us to end of this tutorial. |
| 04:50 | This is Madhu, dubbing for the Spoken Tutorial Project. Thanks for watching. Bye. |
