[Tutorial] [Blitz] For loops

[Cervantes]

For Loops

what they are

For loops are used to execute a code between the 'for' and the 'next' lines. The code is executed a set number of times, decided by the parameters you enter at the 'for' line. For loops also keep track of how many times the code has been repeated in a variable (that doesn't need to be declared beforehand)

Syntax

the first line

code:

For qwerty = 1 To 10

qwerty can be anything you want, as long as it is not a command or already used variable. It is the counter. 1 To 10 sets the number that qwerty begins at, and 10 sets the number that qwerty ends at. This for loops will execute code 10 times.

The last line

code:

Next

Simple enough

you can put whatever code you want between there. It's totally up to you!

Here's an example of code that counts to 5!!!!!!!!!!!!!!!!!!!!!

code:

For number = 1 To 5 Print number Next

You can also count by different intervals, using Step.

code:

For number = 1 To 5 Step 2 Print number Next

"Cervantes! How do I do 'decreasing' like in good ol' turing?!"
You said it! How do you do decreasing?!

code:

For number = 5 to 1 Step -2 Print number Next

tricky huh?

[jonos]

wow, nice tutorial, really makes me understand the syntax.

is there a need for a 'decreasing' word like in turing for a decreasing for loop, or can it just be the same just with a higher first number and lower second number.

[shorthair]

You are doing such an awsome job guys , thanks so much for hte support in here ,these tutorials rock , they are alot easier to understand , unlike mine THIS is awsome you have my seal of approval ( if it means anything to you )

[shorthair]

Psssst , just rename it with " ( Blitz ) " at hte end , to seperate it from dark in case anyone ever does some work with it

[Cervantes]

Sweet! I have the Shorthair seal of approval! Now all I need is a pic of it in my inventory

Jonos: try the following

code:

For i = 1 To 5   Print i Next For k = 5 To 1   Print k Next

It doesn't give you an error, it just doesn't do it.


as for why we need decreasing for loops?

You wrote that lil program that made a boarder, then I made a better one Then I made an EVEN BETTER one!! (I know, its crazy!)

code:

Graphics 400, 400 SetBuffer BackBuffer() x1 = 350 y1 = 50 x2 = 50 y2 = 350 For k = 0 To 350 Step 3   x1 = x1 - 3   y1 = y1 + 3   x2 = x2 + 3   y2 = y2 - 3   Line 50, y1, 50, y1 + 3   Line x1, 50, x1 - 3, 50   Line 350, y2, 350, y2 - 3   Line x2, 350, x2 + 3, 350   Flip Next x1 = 0 y1 = 400 x2 = 400 y2 = 0 For k = 0 To 350 Step 3 x1 = x1 + 3 y1 = y1 - 3 x2 = x2 - 3 y2 = y2 + 3 For i = 0 To 50 Step 3   Plot x1, i   Plot i, y1   Plot x2, i + 350   Plot i + 350, y2 Next Flip Next ;;;;;;;;; While Not KeyHit (1) Wend End

That would have been easier with decreasing for loops. esp the first part. instead of using x1 and y1 and x2 and y2, I could have just used the for variable.

[jonos]

that is some nice stuff there!!! i will give up for now, but just wait...

[jonos]

hey... i found how to do decreasing, i was looking throught the blitz tutorials and i found this, straight from the help, i didn't right it:

You can also step backwards by placing a minus (-) sign after the command with the number of steps backwards you would like to take:

For A = 10 To 0 step -2
Print A
Next

This would print: 10 8 6 4 2 0

[shorthair]

Thats one way to do it , there is a more complex way and it allowy you to add some more cool options , its used when decreasing in hte z axis , but your very right on that decreasing loop , MAKE IT A TUTORIAL