qfedu-c-level/test/d1.c

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#include <stdio.h>
// 这种方式只能交换指针指向的值,不能交换指针本身,而且无法改变实参的值
void swap(int *piA, int *piB)
{
printf("first iA-p: %p, iB-p: %p\n iA: %d,iB: %d\n", piA, piB, *piA, *piB);
int *piC;
piC = piA;
piA = piB;
piB = piC;
printf("after iA-p: %p, iB-p: %p\n iA: %d,iB: %d\n", piA, piB, *piA, *piB);
}
int main()
{
int iA = 100, iB = 200;
printf("main first iA-p: %p, iB-p: %p\n iA: %d,iB: %d\n", &iA, &iB, iA, iB);
int *piA = &iA, *piB = &iB;
swap(piA, piB);
printf("main after iA-p: %p, iB-p: %p\n iA: %d,iB: %d\n", &iA, &iB, iA, iB);
return 0;
}