[C++知识库]【c 结构体数组用法】

#include <iostream>
#include <cstdio>
#include <cstdlib>
using namespace std;

typedef struct {
	int a;
	short b[2];
} Test2;

typedef struct Test1{
	int a;
	char b[3];
	Test2 c;
	struct Test1 *d; 
} Test1;


int main() {
    Test1 x = {10, "Hi", {5, {-1, 25}}, 0};
    Test1 *px = &x;
    cout << &px << endl;
    cout << &px->d << endl;
    Test1 y;
    x.d = &y;

    cout << px->d << endl;          // 野指针，随机值
    cout << &px->d->c.b[0] << endl; // 野指针，随机值
    cout << &px->d->c.b[1] << endl; // 野指针，随机值

    cout << endl; 

    cout << "px->d->c.b[0]: " << px->d->c.b[0] << endl; // 野指针，随机值
    cout << px->d->c.b[1] << endl; // 野指针，随机值

    cout << endl;

    cout << &px->c.b[0] << endl; // -1
    cout << &px->c.b[1] << endl; // 25
    cout << &px->c.b[2] << endl; // 越界

    cout << "px->c.a: " << px->c.a << endl; // 5
    cout << px->c.b[0] << endl; // -1
    cout << px->c.b[1] << endl; // 25
    cout << px->c.b[2] << endl; // 越界, 随机值
    
    cout << endl;
    cout << "px->b[0]: " << px->b[0] << endl; // 'H'
    cout << px->b[1] << endl; // 'i'
    // cout << (int)px->b[2] << endl; // '0'
    printf("px->b[2]: %d\n", px->b[2]);
}

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