用C语言指向Union的指针

待我称王封你为后i 2023-03-05 10:59 21阅读 0赞

## 联盟的指针 **(**Pointer to Union**)** ##

**Pointer to union** can be created just like other pointers to primitive data types.

可以创建**指向联合的指针，**就像指向原始数据类型的其他指针一样。

Consider the below union declaration:

考虑以下联合声明：

union number{
        int a;
        int b;
    };

Here, *a* and *b* are the members of the union *number*.

这里， *a*和*b*是联合*号*的成员。

**Union variable declaration:**

**联合变量声明：**

union number n;

Here, *n* is the variable to *number*.

在这里， *n*是*number*的变量。

**Pointer to union declaration and initialization:**

**联合声明和初始化的指针：**

union number *ptr = &n;

Here, *ptr* is the pointer to the union and it is assigning with the address of the union variable *n*.

在这里， *ptr*是指向并集的指针，并为其分配了并集变量*n*的地址。

**Accessing union member using union to pointer:**

**使用联合指向指针访问联合成员：**

Syntax:
    pointer_name->member;
    
    Example:
    // to access members a and b using ptr
    ptr->a;
    ptr->b;

## 演示联合指针示例的C程序 **(**C program to demonstrate example of union to pointer**)** ##

#include <stdio.h>
    
    int main()
    {
        // union declaration
        union number {
            int a;
            int b;
        };
    
        // union variable declaration
        union number n = { 10 }; // a will be assigned with 10
    
        // pointer to union
        union number* ptr = &n;
    
        printf("a = %d\n", ptr->a);
    
        // changing the value of a
        ptr->a = 20;
        printf("a = %d\n", ptr->a);
    
        // changing the value of b
        ptr->b = 30;
        printf("b = %d\n", ptr->b);
    
        return 0;
    }

**Output:**

**输出：**

a = 10
    a = 20
    b = 30

> 翻译自: [https://www.includehelp.com/c/pointer-to-union-in-c-language.aspx][https_www.includehelp.com_c_pointer-to-union-in-c-language.aspx]

[https_www.includehelp.com_c_pointer-to-union-in-c-language.aspx]: https://www.includehelp.com/c/pointer-to-union-in-c-language.aspx