[EMAIL PROTECTED] schrieb: > Hi its me again (the pane in the ass newbie) > > Where can i get a basic user guide, better yet a sam userguide ? > > i noticed the existence of a def proc in basic can anyone tellme how it works > is it alá qbasic stile ? > > > > thanks
Hi dirty fly, maybe a bit of an answer for you, extracting from Sam Supplement 5. It describes how to use DEF PROCedures. Hopes it helps you. Have a nice day Wo from WoMo-Team DEF PROC (Martin Vale, SAM Supplement 5) The DEFine PROCedure command precedes a block of BASIC instructions that are separate from the rest of the program. Procedures work like GOSUBs. But whereas GOSUB n would execute the subroutine starting at line n, and then return to the statement after the GOSUB instruction when it encounters a RETURN, procedures can have values sent to them in the instruction that called them. For example, SQUARE 3. This would search through the BASIC program for a procedure named SQUARE, carry it out, and return when it reached END PROC. In this example, the procedure SQUARE might simply be DEF PROC SQUARE,x (x being the value sent to it): LET x=SQR x: END PROC. This line could be placed anywhere in the BASIC program. Supposing line 10 was 10 SQUARE 3, the following line might be 20 PRINT x. In this case it would print the square root of 3 (about 2.326). Of course, procedures do not have to have values sent to them. You could have a procedure called WAIT that just consisted of DEF PROC WAIT: PAUSE: END PROC, or a procedure called MATHS which needed 4 variables sent to it eg. a,b,c and d, where the procedure reads DEF PROC MATHS,a,b,c,d: LET answer=a+b*c-d: END PROC. Procedures don't have to be all squashed up on one line. They can contain any number of statements, IF's, GOTO's, GOSUB's, and can even call other procedures. DEFAULT is a command used only inside procedures. It sets a default value for a variable, which is used if no value is sent to the procedure. For example, a procedure called PROMPT might be DEF PROC PROMPT,a,b: DEFAULT a,0.1: DEFAULT a,20:BEEP b,a: END PROC. If this were called with just PROMPT, it would carry out BEEP 0.1,20, if called with PROMPT 10, it would carry out BEEP 10,20, and if it should be called with PROMPT 10,0, it would carry out BEEP 10,0. In this way, procedures can be controlled by setting a DEFAULT value for as little or as many variables as need be for carrying the procedure out. LOCAL is used inside a procedure when the procedure needs thouse variables that are used for other purposes outside the procedure. For example, if your program reads 10 LET a=1 20 PRINT a 30 DO_SOMETHING_PROCEDURE 40 LET a=a+1: GOTO 20 and the procedure named DO_SOMETHING_PROCEDURE used the variable a for another purpose, you would need to insert a LOCAL into the procedure eg. DEF PROC DO_SOMETHING_PROCEDURE: LOCAL a: LET a=4: LET b=a*2: END PROC. This is actually an extremely useless procedure, but it is just used as an example. Because it contains a LOCAL, in this case LOCAL a, it uses the LOCAL variable for whatever it needs to, and then returns it to ist original state when it leaves the procedure. This can be shown by removing the LOCAL, and then RUNning the program.
