//init
void init(void run) {
run();
}
//and being used...
void run() {
}
int main() {
init(run());
return 0;
}
C++, How to make function run another function, eg void func(void func2)
Author
Hi, I want to run a function from a function.
eg.
thanks
You have a problem. Functions can take values as parameters, but void is not a value type (except void *). Furthermore, functions are not values, so you can't pass them - at least, not directly.
Solution? Use a function pointer.
[Edit: source snippet removed.]
Solution? Use a function pointer.
[Edit: source snippet removed.]
Author
Ok, I made my function ok, eg void run(void func()){func();}
But is it possible to store it in a global variable.
eg. something like so:
But is it possible to store it in a global variable.
eg. something like so:
void globalFunc();void doBeep() { Beep(33,33);}int main() { globalFunc = doBeep; globalFunc(); //goes beep return 0;}
ok, first, it's:
void run(void (*func)()){func();}
not:
void run(void func()){func();}
and to answer your question, the way you make a function pointer is
void run(void (*func)()){func();}
not:
void run(void func()){func();}
and to answer your question, the way you make a function pointer is
void (*func)();
Author
Quote:Original post by Roboguy
ok, first, it's:
void run(void (*func)()){func();}
not:
void run(void func()){func();}
and to answer your question, the way you make a function pointer isvoid (*func)();
Thanks it works, but out of curiosity i was wondering what the difference between:
void run(void (*func)()) { func();}//andvoid run(void func()) { func();}is?
And when I'm using the global function pointer, eg
void (*func)();void doBeep() { Beep(200,50);}void run(void (*func)()) { func();}int WINAPI WinMain( HINSTANCE hInst, HINSTANCE, LPSTR, INT ){ func = doBeep; //do i do this or func = &doBeep; // as they both work. run(func); return 0;}
One can't pass a function by value, it needs to be a function pointer [though the [std?] notation would suggest otherwise].
func = &doBeep fits better with standard notation, but func = doBeep seems to be standard aswell, so why not?
"1) The second one doesn't work"
Nope, that works perfectly. It's a completely valid syntax.
Nope, that works perfectly. It's a completely valid syntax.
This topic is closed to new replies.
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