 Loops are used to
loop around .. duh, well they are really used when you want to keep
repeating something, until a
condition. |
Here are some loop structures visual basic provides you with:
| loop name | how to set it up |
| Do | Do Stuff you want to do Loop |
| Do While | Do While Condtion Stuff you want to do Loop |
| Loop Until | Do stuff you want to do Loop Until Condition |
| For | For Condtion =
Value to Condtion =
Value stuff you want to do Next Condtion |
The
do loop is the most basic loop visual basic
provides us with, it keeps going
until you stop it.
|
Do |
| 1. We
Told Visual Basic that a DO loop is being started, by entering
Do. 2. We tell Visual Basic, what we want to do when it beggins looping, we told it to send a message box with the prompt "Hello". 3. We tell Visual Basic that were done inserting things to do, and we want it to loop back to the do part. |
The
do while loop is very useful when you want to start a
loop, and continue it
if the condition is met.
|
Do While X < 5 |
| 1. We
tell Visual Basic that we want to loop as long as the variable X is less
then 5. 2. We tell Visual Basic what we want to do when the loop is executed, well tell vb to send a message box up. 3. We add one (1) to the variable X, because if we didnt increase X, the condition will always be less then 5, therefore, the loop will loop endlessly. 4. We tell visual basic that we are done inserting what to do, and we want it to loop back to do now. |
The loop until loop is basically
the same as the do while
loop, instead it tests the condition at the end of
the loop.
|
Do |
| 1. We
tell Visual Basic that we want to start a Loop. 2. We tell VB that we want to send a message box up, everytime the loop is looped. 3. We increment the variable X by 1, because we want the loop to end sometime this century. 4. We tell the loop to stop when the counter variable X = 5. |
This is one of the more advanced
loops, but also one of the most widely used ones...
|
For X = 1 to X <=
5 |
| 1. We
declare what the counter variable is (x=1), and tell vb to loop while its
less then or equal to 5. (x <= 5) 2. We tell vb that we want to send a message box up, everytime the loop is looped. 3. We increment the counter variable X by 1, so the loop will stop once the condition is met. 4. We tell VB to loop. Now, when it loops x is incremented so we want vb to do the next x. It's kind of confusing to explain the logic behind the statement "Next x". But, as X increments or decrements, the Next is telling the loop to goto the Next "x" in the loop, dont worry you don't need to know that! |
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