Wie verwendet man den Schalter in C++?

Question

Wie verwende ich Switch Case in diesem Code? Ich habe es mehrmals versucht, aber ich weiß wirklich nicht, wie ich es ohne Fehler machen kann.

#include<iostream.h> 
int x,y; 
int sum(int a,int b) 
{ 
    int c; 
    c = a+b; 
    return (c); 
} 
int sub (int a ,int b) 
{ 
    int c; 
    c = a-b ; 
    return (c); 
} 
int multi (int a, int b) 
{ 
    int c ; 
    c = a*b; 
    return (c); 
} 
float div (int a , int b) 
{ 
    float c; 
    c = a/b ; 
    return (c); 
} 
main() 
{ 
    cout<<"enter the value of x = "; 
    cin>>x; 
    cout<<"enter the value of y = "; 
    cin>>y; 
    cout<<"x + y = "<< sum(x,y); 
    cout<<"\n x - y = "<< sub(x,y); 
    cout<<"\n x * y = "<< multi(x,y); 
    cout<<"\n x /y = "<< div (x,y); 
    cin>>"\n"; 
} 

Answer 1

In Ihrem Haupt einen Schalter, hinzufügen und jede case-Anweisung eines Funktionsaufruf (Link sum(), multi(), usw.) machen.

Was man wollte:

#include <iostream> 
using namespace std; 

int x,y; 
int sum(int a,int b) 
{ 
int c; 
c = a+b; 
return (c); 
} 
int sub (int a ,int b) 
{ 
int c; 
c = a-b ; 
return (c); 
} 
int multi (int a, int b) 
{ 
int c ; 
c = a*b; 
return (c); 
} 
float div1(int a , int b) 
{ 
float c; 
    c = a/b ; 
return (c); 
} 
main() 
{ 
    int ch=0; 
std::cout <<"enter the value of x = "; 
std::cin >>x; 
std::cout <<"enter the value of y = "; 
std::cin >>y; 
std::cout <<"Input"<<std::endl; 
std::cout <<"Sum: 1, Subtract: 2, Product: 3, Divide: 4"<<std::endl; 
std::cin >>ch; 
switch(ch){ 
case 1: 
    std::cout <<"x + y = "<< sum(x,y) <<std::endl;break; 
case 2: 
    std::cout <<"x - y = "<< sub(x,y) <<std::endl;break; 
case 3: 
    std::cout <<"x * y = "<< multi(x,y) <<std::endl;break; 
case 4: 
     if(y!=0){ 
      std::cout <<"x /y = "<<div1(x,y)<<std::endl; 
     } else { 
      std::cout <<"Denominator can't be zero is 0"<<std::endl; 
    } 
    break; 
default: 
    std::cout <<std::endl; 
} 
}