bool operator!=(Complex& D) { return(*this != D); }这样写有问题吗

在这个上下文中，`operator!=` 是用于比较两个 `num_item_stu` 或者 `NumItem` 对象的不等于操作符。然而，您给出的代码片段似乎是在讨论 `Complex` 类型的操作符重载，但这里引用的内容与 `num_item_stu` 相关。因此，如果您的意图是针对 `Complex` 类型的，那么这段代码应该写成：

bool Complex::operator!=(const Complex& D) {
    return (*this) != D;
}

这表示对 `Complex` 类的一个实例（`*this`）与另一个 `Complex` 实例 `D` 进行不等于（`!=`）比较。如果两者相等则返回 `false`，反之返回 `true`。

需要注意的是，如果您的类名为 `num_item_stu` 或 `NumItem`，并且想要定义 `!=` 操作符，你应该按照类似的方式重载它：

// 如果是 num_item_stu 或 NumItem 类
bool num_item_stu::operator!=(const num_item_stu& other) {
    return (this->num != other.num) && (this->type != other.type);
}

相关问题

#include<iostream> using namespace std; class Complex { private: double real, image; public: Complex(double rel = 0, double img = 0) { real = rel; image = img; } void display() { cout << "(" << real; if (image > 0) cout << "+" << image << "*i)"; else if (image < 0) cout << image << "*i)"; else cout << ")"; } friend Complex operator -( Complex& c1, const Complex& c2); friend Complex operator /( Complex& c1, const Complex& c2); friend Complex operator ==(Complex& c1, Complex& c2); friend Complex operator !=(Complex& c1, Complex& c2); friend ostream operator <<(Complex& c1, Complex& c2); }; Complex operator -( Complex& c1, const Complex& c2) { Complex temp; temp.real = c1.real - c2.real; temp.image = c1.image - c2.image; return temp; } Complex operator /( Complex& c1, const Complex& c2) { Complex FFF; FFF.real = c1.real / c2.real; FFF.image = c1.image / c2.image; return FFF; } int main() { Complex c1(10, 9), c2(3, -4), c3; c3 = c1 / 5; c1.display(); cout << "/"; cout << 5; cout << "="; c3.display(); cout << endl; return 0; //输出比较的结果 cout<<"c1==c2 ? 结果:"; cout<<(c1==c2)<<endl; cout<<"c1!=c2 ? 结果:"; cout<<(c1!=c2)<<endl; }严重性 代码 说明 项目 文件 行 禁止显示状态 错误 C2678 二进制“<<”: 没有找到接受“std::ostream”类型的左操作数的运算符(或没有可接受的转换)帮我修改并给出正确代码

需要将友元函数的返回类型改为 ostream&，并在函数内部将输出语句改为 return os，同时在 main 函数内输出对象的语句需要改为 cout << c1 << endl; 和 cout << c2 << endl;。代码如下：

#include<iostream>  
using namespace std;   

class Complex {  
private:      
    double real, image;  
public:      
    Complex(double rel = 0, double img = 0) {          
        real = rel;          
        image = img;      
    }      
    void display() {          
        cout << "(" << real;          
        if (image > 0)              
            cout << "+" << image << "*i)";          
        else if (image < 0)              
            cout << image << "*i)";          
        else              
            cout << ")";      
    }       
    friend Complex operator -(Complex& c1, const Complex& c2);      
    friend Complex operator /(Complex& c1, const Complex& c2);      
    friend bool operator ==(Complex& c1, Complex& c2);     
    friend bool operator !=(Complex& c1, Complex& c2);     
    friend ostream& operator <<(ostream& os, Complex& c); 
};   

Complex operator -(Complex& c1, const Complex& c2) {      
    Complex temp;      
    temp.real = c1.real - c2.real;      
    temp.image = c1.image - c2.image;      
    return temp;  
}   

Complex operator /(Complex& c1, const Complex& c2) {      
    Complex FFF;      
    FFF.real = c1.real / c2.real;      
    FFF.image = c1.image / c2.image;      
    return FFF;  
}   

bool operator ==(Complex& c1, Complex& c2) {
    return (c1.real == c2.real) && (c1.image == c2.image);
}

bool operator !=(Complex& c1, Complex& c2) {
    return !(c1 == c2);
}

ostream& operator <<(ostream& os, Complex& c) {
    os << "(" << c.real;
    if (c.image > 0)
        os << "+" << c.image << "*i)";
    else if (c.image < 0)
        os << c.image << "*i)";
    else
        os << ")";
    return os;
}

int main() {      
    Complex c1(10, 9), c2(3, -4), c3;      
    c3 = c1 / 5;      
    c1.display();      
    cout << "/";      
    cout << 5;      
    cout << "=";      
    c3.display();      
    cout << endl; 

    cout << "c1 == c2 ? 结果:";
    cout << (c1 == c2) << endl;
    cout << "c1 != c2 ? 结果:";
    cout << (c1 != c2) << endl;

    cout << c1 << endl;
    cout << c2 << endl;
    
    return 0;
}

#include <iostream> using namespace std; class Complex { private: double real,image; //分别为实部、虚部 public: Complex(double rel=0, double img=0) { real=rel; image=img; } void display() //输出(a+b*i) 、(a-b*i) 、(a)等形式 { cout<<" ("<<real; if (image>0) cout<<"+"<<image<<"*i) "; //虚部为正 else if (image<0) cout<<image<<"*i) "; //虚部为负 else cout<<") "; //虚部为0，即为实数 } friend Complex operator -(Complex & c1,Complex & c2);//用友元函数重载 }; //友元函数的定义 Complex operator -(Complex & c1,Complex & c2) { Complex temp; temp.real=c1.real-c2.real; temp.image=c1.image-c2.image; return temp; } int main() { Complex c1(10,9), c2(3,-4),c3; c3=c1/5; //输出除的结果 c1.display(); cout<<"/"; cout<<5; cout<<"="; c3.display(); cout<<endl; //输出比较的结果 cout<<"c1==c2 ? 结果:"; cout<<(c1==c2)<<endl; cout<<"c1!=c2 ? 结果:"; cout<<(c1!=c2)<<endl; return 0; }

这段代码存在一个问题，即在主函数中调用了一个未定义的除法运算符“/”。同时，代码中定义了一个友元函数，用于重载减法运算符“-”，但是并没有使用该运算符，因此友元函数定义也无意义。

以下是修改后的代码：

#include <iostream> 
using namespace std; 

class Complex { 
private: 
	double real, image; // 分别为实部、虚部 

public: 
	Complex(double rel = 0, double img = 0) 
	{ 
		real = rel; 
		image = img; 
	} 

	void display() // 输出(a+b*i)、(a-b*i)、(a)等形式 
	{ 
		cout << " (" << real; 
		if (image > 0) 
			cout << "+" << image << "*i) "; // 虚部为正 
		else if (image < 0) 
			cout << image << "*i) "; // 虚部为负 
		else 
			cout << ") "; // 虚部为0，即为实数 
	} 

	// 重载减法运算符“-” 
	Complex operator-(Complex& c) {
		Complex temp;
		temp.real = real - c.real;
		temp.image = image - c.image;
		return temp;
	}

	// 重载相等运算符“==”
	bool operator==(Complex& c) {
		return (real == c.real) && (image == c.image);
	}

	// 重载不等运算符“!=”
	bool operator!=(Complex& c) {
		return !(*this == c);
	}
}; 

int main() { 
	Complex c1(10, 9), c2(3, -4), c3; 

	c3 = c1 - c2; // 使用重载的减法运算符“-” 
	c1.display(); 
	cout << "-"; 
	c2.display(); 
	cout << "="; 
	c3.display(); 
	cout << endl; 

	cout << "c1==c2 ? 结果:"; 
	cout << (c1 == c2) << endl; 

	cout << "c1!=c2 ? 结果:"; 
	cout << (c1 != c2) << endl; 

	return 0; 
}

修改后的代码中，重载了减法运算符“-”，并在主函数中使用该运算符计算了两个复数的差。同时，还重载了相等运算符“==”和不等运算符“!=”，并在主函数中使用这两个运算符比较了两个复数的大小关系。