pointfun.c

来自「C源码集」· C语言 代码 · 共 31 行

#include <stdio.h>

void change (int *p);
//prototype says that change will not return a value and it expects
//to be given a pointer to an integer, i.e. the address of an integer


int main ()
{
	int var = 5;

	printf("Before change, var is %i \n", var);

	change(&var);
	//call the function change. Send it the address of var

	printf("After change, var is %i\n", var);

	return 0;
}

void change (int *p)
{
	*p *= 100;
	// what p points to becomes itself * 100

	printf("In change, *p is %i\n", *p);

	//change doesn't know anything about var
	//but it does know the place p points to
}