Cplusplus 简明教程

C++ Declare Multiple Variables

C++ programming language 允许程序员在一个声明中声明多个 variables ，而无需任何换行符。这仅适用于属于同一 data type 的变量。

C++ programming language allows programmers to declare multiple variables in a single statement without any line breaks. This is only possible for variables which belong to the same data type.

How to Declare Multiple Variables in C++?

这是使用带有不同变量名的变量逗号 (,) 分隔列表来执行的，并且必须为要被声明的所有变量使用相同的数据类型。对 C++ 中的所有数据类型支持多个变量的声明，例如，我们可以在一个声明中使用逗号分隔列表，使用不同的名称来声明多个 strings 。

This is executed using a comma (,) separated list of variables with different variables names, and the data types must be the same for all variables to be declared. Multiple variables declaration is supported for all data types in C++, for example, we can declare multiple strings with different names in a single statement using a comma separated list.

Syntax

以下语法显示了如何在单个声明中声明具有相同数据类型的多变量 −

The following syntax shows how to declare multiple variables with same data types in a single statement −

data_type var_a, var_b, var_;

Example

以下示例代码显示了如何在单个声明中声明具有相同数据类型的多变量 −

The following exemplar code shows how to declare multiple variables with same data types in a single statement −

#include <iostream>
using namespace std;

int main() {
   int y,z,x;

   x=10;
   y=20;
   z=30;

   cout<<"value of x: "<<x<<endl<<"value of y: "<<y<<endl<<"value of z: "<<z;

   return 0;
}

value of x: 10
value of y: 20
value of z: 30

Initialize Multiple Variables

变量也可以在声明的同一语句中用不同值初始化，这使得可以轻松声明不同值的变量。

The variables can also be initialized with different values in the same statement of declaration, which makes it easy to declare variables of different values.

Syntax

以下语法显示了如何在单个声明中声明多个变量，并在其中用值对它们进行初始化 −

The following syntax shows how to declare multiple variables, and initialize them with values in a single statement −

data_type var_a=[value1], var_b, var_c=[value3];

这里，var_a、var_b 和 var_c 是相同数据类型的变量，而 [value] 是该变量的值。

Here, var_a, var_b and var_c are variables of same data type, and [value] is the value of that variable.

Example

以下示例代码显示了如何在单个声明中声明多个变量，并在其中用值对它们进行初始化 −

The following exemplar code shows how to declare multiple variables, and initialize them with values in a single statement −

#include <iostream>
using namespace std;

int main() {
   int y=10,z=20,x;
   x=10;
   cout<<"value of x: "<<x<<endl<<"value of y: "<<y<<endl<<"value of z: "<<z;

   return 0;
}

value of x: 10
value of y: 10
value of z: 20

Initialize Multiple Variables with Same Value

变量也可以在单个声明中使用 "=" 运算符多次，用相同的值对其进行初始化。

The variables can also be initialized with the same values in a single statement using the "=" operator multiple times in a single statement.

Syntax

以下语法显示了如何在单个声明中声明多个变量，并将它们全部初始化为单个值 −

The following syntax shows how to declare multiple variables and initialize all of them to a single value in a single statement −

data_type var_1, var_2, var_3;
var_1=var_2=var_3= [value]

这里，变量 var_1、var_2 和 var_3 在单个声明中初始化为单个值 [value]。

Here, the variables var_1, var_2 and var_3 are initialized to a single value [value] in a single statement.

Example

以下示例代码显示了如何在单个声明中声明多个变量，并将它们全部初始化为单个值 −

The following exemplar code shows how to declare multiple variables and initialize all of them to a single value in a single statement −

#include <iostream>
using namespace std;

int main() {
   int y,z;
   int x=y=z=10;
   cout<<"value of x: "<<x<<endl<<"value of y: "<<y<<endl<<"value of z: "<<z;

   return 0;
}

value of x: 10
value of y: 10
value of z: 10