int* p 与 int** p的区别_int *p和(int *)p-优快云博客

本文通过两个不同的C++示例程序展示了不同类型指针的使用方法及它们如何影响原始变量和引用。探讨了基本指针、指向指针的指针及引用的变化，并分析了这些变化对数组元素的影响。

#include <iostream>
using namespace std;

int func(int i1,int* pi21,int* &pi22,int &ri3,char* str)
{
    cout << "------------------------------------\n";
    cout << "i1,*pi21,*pi22,ri3,str = " << i1 << " " << *pi21 << " " << *pi22 << " " << ri3
         << " " << str << endl;
    i1++;
    pi21++;
    pi22++;
    ri3++;
    (*str)++;
    cout << "----------------------------------------\n" << endl;
    cout << "i1,*pi21,*pi22,ri3,str = " << i1 << " " << *pi21 << " " << *pi22 << " " << ri3
         << " " << str << endl;

    i1++;
    (*pi21)++;
    (*pi22)++;
    ri3++;
    str++;

    cout << "----------------------------------------\n" << endl;
    cout << "i1,*pi21,*pi22,ri3,str = " << i1 << " " << *pi21 << " " << *pi22 << " " << ri3
         << " " << str << endl;
    return i1;

}

int main()
{
    int i = 1,a[2] = {21,202},*pa = a,b[2] = {21,202},*pb = b,r = 3456;
    char s[]= "ABCDEFG";
    cout << "---------------------------------\n";
    cout << "i,*pa,*pb,r,s = " << i << " " << *pa << " " << *pb << " " << r << " " << s << endl;
    cout << "a[0],a[1],b[0],b[1] = " << a[0] << " " << a[1] << " " << b[0]
         << " " << b[1] << endl;
    int tmp = func(i,pa,pb,r,s);
    cout << "----------------------------------\n";
    cout << "i,*pa,*pb,r,s = " << i << " " << *pa << " " << *pb << " " << r << " " << s << endl;
    cout << "a[0],a[1],b[0],b[1] = " << a[0] << " " << a[1] << " " << b[0]
         << " " << b[1] << endl;

cout << "tmp = " << tmp << endl;
return 0;
}

#include <iostream>
using namespace std;

int func(int i1,int** pi21,int* &pi22,int &ri3,char* str)
{
    cout << "------------------------------------\n";
    cout << "i1,*pi21,*pi22,ri3,str = " << i1 << " " << *pi21 << " " << *pi22 << " " << ri3
         << " " << str << endl;
    i1++;
    (*pi21)++;
    pi22++;
    ri3++;
    (*str)++;
    cout << "----------------------------------------\n" << endl;
    cout << "i1,*pi21,*pi22,ri3,str = " << i1 << " " << *pi21 << " " << *pi22 << " " << ri3
         << " " << str << endl;

    i1++;
    (**pi21)++;
    (*pi22)++;
    ri3++;
    str++;

}

int main()
{
    int i = 1,a[2] = {21,202},*pa = a,b[2] = {21,202},*pb = b,r = 3456;
    char s[]= "ABCDEFG";
    cout << "---------------------------------\n";
    cout << "i,*pa,*pb,r,s = " << i << " " << *pa << " " << *pb << " " << r << " " << s << endl;
    cout << "a[0],a[1],b[0],b[1] = " << a[0] << " " << a[1] << " " << b[0]
         << " " << b[1] << endl;
    int tmp = func(i,&pa,pb,r,s);
    cout << "----------------------------------\n";
    cout << "i,*pa,*pb,r,s = " << i << " " << *pa << " " << *pb << " " << r << " " << s << endl;
    cout << "a[0],a[1],b[0],b[1] = " << a[0] << " " << a[1] << " " << b[0]
         << " " << b[1] << endl;

cout << "tmp = " << tmp << endl;
return 0;
}

以上两种情况的输出结果不同。