它说“没有用于'Fraction'初始化的匹配构造函数

Question

.cpp

//
// calculator.cpp
//
#include "Fraction.h"
#include<iostream>
#include<stdexcept>
using namespace std;

int main()
{

    Fraction x,y; //ERROR IS RIGHT HERE. It says "No matching constructor for initialization of 'Fraction' 
    char op;
    try
    {
        cin >> x;
        cin >> op;
        while ( cin && ( op == '+' || op == '-' ) )
        {
            cin >> y;
            if ( op == '+' )
                x = x + y;
            else
                x = x - y;
            cin >> op;
        }
        cout << x << endl;
    }
    catch ( invalid_argument& e )
    {
        cout << "Error: " << e.what() << endl;
    }
}

.h

#ifndef Fraction_Calculator_Fraction_h
#define Fraction_Calculator_Fraction_h
#include<iostream>
#include<cstdlib>

//Fraction class definition
class Fraction
{
public:

    Fraction (int a, int b);
    int fraction(int a, int b);
    void set(int, int);
    int get_numerator(void);
    int get_denomenator(void);
    int find_gcd (int n1, int n2);
    void reduce_fraction(int nump,  int denomp);
    Fraction& operator+(const Fraction& n);
    Fraction& operator-(const Fraction& n);
    friend std::ostream& operator<<(std::ostream &os, const  Fraction& n);
    friend std::istream& operator>>(std::istream &is, Fraction& n);
    Fraction& operator= (const Fraction& n);
    int denom;
    int numera;

private:
    int numerator;
    int denomenator;
    int denomp;
    int nump;

};

#endif

它说＆＃34;没有匹配的构造函数用于初始化＆＃39;分数＆＃39;在cpp文件的第一行 我不明白这意味着什么。

Answer 1

问题是你的Fraction构造函数需要2个参数。

Fraction (int a, int b);

并且您在没有

的情况下调用它

Fraction x,y; //ERROR IS RIGHT HERE. It says "No matching constructor for initialization of 'Fraction' 

您应该使用2个int参数调用x和y，或者定义另一个不带参数的构造函数。

Answer 2

提供默认构造函数     分数（）     {      分子= 0;      denomenator0;      denomp0;      NUMP = 0;     }