指针做形参

swap(int a, int b){    int t = a;    a = b;    b = t;} swap1(int *a, int *b){        int t = *a;    *a = *b;    *b = t; }int main(){    int a=2, b =3;    swap(a,b);//不能实现a和b值的互换    swap1(&a,&b);//可以实现a和b值的互换    return 0;}