[fpc-devel] void test( void *data ) to procedure test( var data); ? is it safe ?
skybuck2000 at hotmail.com
Mon Jun 20 18:11:35 CEST 2011
The difference is actually:
1. Pascal has call by value and call by reference.
2. C only has call by value.
Because of limitation 2, C programmers use the pointer trick to pass the
address of a variable so it can be changed inside the routine, example:
1. C call by value (default):
void test( int a )
a = 5; // after routine exists, value is lost.
test( b );
2. C call by value (reference trick):
void test( int *a ) <- pointer to variable of integer trick.
*a = 5;
test( &b ); // <- address of variable trick.
For noobies/novice programmers this makes C a bad language since
noobies/novice programmers are still learning to design software codes and
will often need to change call by value to call by reference or vice versa
and then it becomes a hurdle to change all these call sites, not mention
For experienced programmers it's also a reall burden to use * everywhere and
& everywhere, everywhere reference comes into play.
Passing real pointers and working with them becomes even more tricky and
requires even more stars/asterixes.
A very bad problem which was easily solved in pascal:
procedure test( var a : integer );
a := 5;
test( a );
^ No stupid symbols needed ! ;) Much user friendly and pretty much does the
Why make things more difficult then absolutely necessary huh ?! ;) :) =D
Only thing I can imagine is very very very maybe it's easier to write a
"call by value compiler" than a "call by reference compiler" ?!? But does
sound a bit like bullshit to me ?! ;) :)
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