构造函数参数默认值编译失败_在C ++中使用默认，参数化和复制构造函数设置数据成员的值...

Dear 丶 2023-03-05 05:30 25阅读 0赞

构造函数参数默认值编译失败

**Create a class and set values to the private data members using a default, parameterized and copy constructor in C++**.

**使用C ++中的默认，参数化和复制构造函数创建一个类并为私有数据成员设置值** 。

This is an example of C++ constructors, here we have a class named person and private data members name and age. In this example, we will set values to name and age through the **default, parameterized and copy constructors**.

这是C ++构造函数的示例，这里有一个名为person的类，私有数据成员name和age 。 在此示例中，我们将通过**默认，参数化和复制构造函数**将值设置为name和age 。

Here, we will create three objects p1, p2 and p3. p1 will be initialized with a default constructor, p2 will be initialized with a parameterized constructor and p3 will be initialized with the copy constructor.

在这里，我们将创建三个对象p1 ， p2和p3 。 p1将使用默认构造函数初始化， p2将使用参数化构造函数初始化， p3将使用复制构造函数初始化。

**Program:**

**程序：**

#include <iostream>
    #include <string.h>
    using namespace std;
    
    class person{
        
    	private:
    		char name[30];
    		int age;
    	
    	public:
    		//default constructor
    		person(){
        
    			strcpy(name,"None");
    			age = 0;
    		}
    		//parameterized constructor
    		person(char n[], int a){
        
    			strcpy(name, n);
    			age = a;
    		}
    		//copy constructor
    		person(person &p){
        
    			strcpy(name, p.name);
    			age =p.age;
    		}
    		//function to display person details
    		void print(void){
        
    			cout<<name<<" is "<<age<<" years old."<<endl;
    		}
    };
    
    //Main function
    int main(){
        
    	//creating objects
    	person p1; //default constructor will be called
    	person p2("Amit Shukla",21); //parameterized constructor will be called
    	person p3(p2); //copy constructor will be called
    	
    	//printing
    	cout<<"object p1..."<<endl;
    	p1.print();
    	cout<<"object p2..."<<endl;
    	p2.print();	
    	cout<<"object p3..."<<endl;
    	p3.print();	
    	
    	return 0;
    }

**Output**

**输出量**

object p1...
    None is 0 years old.
    object p2...
    Amit Shukla is 21 years old.
    object p3...
    Amit Shukla is 21 years old.

> 翻译自: [https://www.includehelp.com/cpp-programs/set-values-of-data-members-using-default-parameterized-and-copy-constructor.aspx][https_www.includehelp.com_cpp-programs_set-values-of-data-members-using-default-parameterized-and-copy-constructor.aspx]

构造函数参数默认值编译失败

[https_www.includehelp.com_cpp-programs_set-values-of-data-members-using-default-parameterized-and-copy-constructor.aspx]: https://www.includehelp.com/cpp-programs/set-values-of-data-members-using-default-parameterized-and-copy-constructor.aspx