Chandrika: Created page with '{| border=1 !Time !Narration |- |0:00 |Hello and welcome. I have decided to create seperate tutorials for each looping statement. |- |0:07 |I want to keep it simple. This will b…'

2012-11-29T06:34:43Z

Created page with '{| border=1 !Time !Narration |- |0:00 |Hello and welcome. I have decided to create seperate tutorials for each looping statement. |- |0:07 |I want to keep it simple. This will b…'

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{| border=1
!Time
!Narration
|-
|0:00
|Hello and welcome. I have decided to create seperate tutorials for each looping statement.
|-
|0:07
|I want to keep it simple. This will be useful as a reference also if you need to refer to how a particular loop works.
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|0:22
|In this tutorial, we will learn about the WHILE loop
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|0:25
|A WHILE loop checks for a condition at the start at the loop and executes the code depending on whether this condition is True or not
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|0:35
|for example I'll start my 'WHILE loop' here and this is the condition and this is my block
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|0:44
|I'll represent my block between curly brackets
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|0:52
|My condition is here. Now, in the 'IF statement', for example I used 1=1.
|-
|1:02
|Now if I say 'test' or 'loop' here.
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|1:08
|There is a loop here and then a break. Now what happens is as long as 1=1, it would create a loop
|-
|1:14
|If I do something here, lets try this.
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|1:19
|It would probably crash your browser because the loop would be repeated as long as 1=1 and for infinite no. of times, 1 will always equal 1
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|1:29
|So since the loop will always be repeated, your browser will crash
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|1:33
|Lets say while a variable, 'num' is smaller or equal to 10 and under echo i can say - 'num ++'
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|1:57
| '++' is an arithmetical operator. And what it basically does is, it increases num by 1. It is the same as writing 'num =num +1'
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|2:16
|So it takes num and says that it is equal to the value of num plus 1.
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|2:22
|So this again is an arithmetical operator. What's going to happen is -
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|2:29
|We are going to say 'num' lesser than or equal to '10', if yes then echo loop and then say add 1 on to the variable num
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|2:46
|But what we should really do is create 'num = 1' at the moment. So loop once at 1. This will then equal 2 then 3 then 4 all the way up to 10 and then it will stop
|-
|3:02
|After that the rest of the code below this will continue
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|3:06
|So we said this 1 and see what will we get. Okay we got a loop 1,2,3,4,5,6,7,8,10 times
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|3:20
|Now to make it more fun I'll say loop 1 and I'll concatenate 'num' to the end of that
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|3:29
|In fact let's make it simpler and say 'num' inside - it will make it easier to read
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|3:37
|Okay I'll say loop 1 and add 1 and then I'll say loop 2 and I'll add another 1; that's loop 3 add another 1 up to 10.
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|3:49
|Lets open this up. Refresh it. There you go. You got loop 1,2,3 all the way up to 10 as you can see
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|3:57
|Lets change this value here to 100. Refresh that. You can see it has gone to hundred. The bigger the number, the longer it will take to loop
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|4:09
|Let's take 6000. Let's refresh that. It's going to take a while. There you go - up to 6000. So it's very efficient in this way
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|4:20
|You can try combining this with an 'array' to create a program that echoes out of the alphabet inside the 'array'
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|4:33
|You can use loops to echo out every single value of an array
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|4:36
|Just give it a go. I will probably do this in one my tutorial - not in the basics section though
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|4:45
|However, this is the basics structure. What I also recommend you to do is create a variable here called 'max' and put your maximum value here
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|4:54
|It will do exactly the same thing. It's just a lot more easy to read and you can declare all this here and this would be a reference to it
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|5:02
|If you have more than 1 loop. I prefer it for readability and flexibility for my program. Okay so that's a WHILE loop. Let me summarise. It checks the condition of the start
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|5:15
|If that condition is True. it would execute this block of code and you can do things like 'echo alpha'
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|5:21
|Your variable is being incremented. Make sure that you do increment your variable otherwise it will loop for infinity.
|-
|5:31
|Thanks for watching. This is Sidharth for the Spoken Tutorial Project, signing off. Goodbye.
|-

PHP-and-MySQL/C2/Loops-While-Statement /English - Revision history

Chandrika: Created page with '{| border=1 !Time !Narration |- |0:00 |Hello and welcome. I have decided to create seperate tutorials for each looping statement. |- |0:07 |I want to keep it simple. This will b…'