문제
Just learning C++, and I'm enjoying making my first program it's not much, it just solves math problems I'm having some issues with the distance formula as far as I know my logic is right sqrt((x2-x1)+(y2-y1)). However I am getting the error
error C2113: '-' : pointer can only be subtracted from another pointer which is throwing me off.
BONUS question... if anybody could point me to a method of directing users back to the first menu when they have finished with a previous selection that would be cool. I'm assuming some sort of loops but I haven't covered that yet in my C++ class.
Here is the code(sorry if it is messy but I haven't learned proper formatting yet)
https://stackoverflow.com/questions/19824557
italiano
english
français
española
中国
日本の
العربية
Deutsch
한국어
Português
Russian#include "stdafx.h"
#include <iostream>
#include <cstdlib>
#include <cmath>
using namespace std;
int selection;
int choice;
int choice2;
double height;
double length;
double a;
double x;
double y;
double const pi = 3.14;
double r;
double m;
double x1;
double x2;
double y1;
double y2;
double distance;
int main(){
cout<<"-------------------------"<<endl;
cout<<" MATH DESTROYER "<<endl;
cout<<"-------------------------"<<endl;
cout<<" 1-Geometry Solver "<<endl;
cout<<" 2-Algebra Solver "<<endl;
cout<<" 3-"<<endl;
cout<<endl;
cout<<" Select Option number: "<<endl;
cin>>selection;
cout<<endl;
cout<<endl;
switch(selection){
case 1:
cout<<"-------------------------"<<endl;
cout<<" GEOMETRY SOLVER ";cout<<endl;
cout<<endl;
cout<<" 1-Perimeter of a square "<<endl;
cout<<" 2-Area of a square "<<endl;
cout<<" 3-Perimeter of a rectangle"<<endl;
cout<<" 4-Area of a rectangle "<<endl;
cout<<" 5-Perimeter of a circle "<<endl;
cout<<" 6-Area of a circle "<<endl;
cout<<" Select Option number: "<<endl;
cout<<"-------------------------"<<endl;
cin>>choice;
cout<<endl;
cout<<endl;
switch(choice){
case 1:
cout<<"-------------------------"<<endl;
cout<<" PERIMITER OF A SQUARE "<<endl;
cout<<endl;
cout<<"Enter Height"<<endl;
cin>>height;
cout<<"Enter Length"<<endl;
cin>>length;
cout<<"Perimiter of Square ="<<(height*2)+(length*2)<<endl;
cout<<"-------------------------"<<endl;
cout<<endl;
cout<<endl;
system("pause");
return 0;
case 2:
cout<<"AREA OF A SQUARE"<<endl;
cout<<endl;
cout<<"Enter Length"<<endl;
cin>>length;
cout<<endl;
cout<<endl;
cout<<"FORMULA L^2";
cout<<endl;
cout<<endl;
cout<<"AREA of Square ="<<pow(length,2)<<endl;//(pow)(length,2)= length to the power of 2 or lenght^2
cout<<endl;
cout<<endl;
system("pause");
return 0;
case 3:
cout<<"PERIMITER OF A RECTANGLE"<<endl;
cout<<endl;
cout<<"Enter Height"<<endl;
cin>>height;
cout<<"Enter Length"<<endl;
cin>>length;
cout<<endl;
cout<<endl;
cout<"FORMULA L2+H2";
cout<<endl;
cout<<endl;
cout<<"Perimiter of Rectangle ="<<(height*2)+(length*2)<<endl;
cout<<endl;
cout<<endl;
system("pause");
return 0;
case 4:
cout<<"AREA OF A RECTANGLE"<<endl;
cout<<endl;
cout<<"Enter Height"<<endl;
cin>>height;
cout<<"Enter Length"<<endl;
cin>>length;
cout<<endl;
cout<<endl;
cout<"FORMULA L2+H2";
cout<<endl;
cout<<endl;
cout<<"Perimiter of Rectangle =" <<height*length<<endl;
cout<<endl;
cout<<endl;
system("pause");
return 0;
case 5:
cout<<"PERIMITER OF A CIRCLE"<<endl;
cout<<endl;
cout<<"Enter Radius"<<endl;
cin>>r;
cout<<endl;
cout<<endl;
cout<<"FORMULA peremiter=PI X D";
cout<<endl;
cout<<endl;
cout<<"Perimiter of circle ="<<pi*(r*2)<<endl;
cout<<endl;
cout<<endl;
system("pause");
return 0;
case 6:
cout<<"AREA OF A CIRCLE"<<endl;
cout<<endl;
cout<<"Enter Radius"<<endl;
cin>>r;
cout<<endl;
cout<<endl;
cout<<"FORMULA PI X R^2";
cout<<endl;
cout<<endl;
cout<<"Area of Circle ="<<pi*(pow(r,2))<<endl;
cout<<endl;
cout<<endl;
system("pause");
return 0;
}
case 2:
cout<<" ALGEBRA MASTER "
cout<<"-------------------------"<<endl;
cout<<" 1-Distance Formula "<<endl;
cout<<" 2-Slope "<<endl;
cout<<" 3-Pythagorean Theorm "<<endl;
cout<<"-------------------------"<<endl;
cout<<endl;
cout<<"Select Option number:"<<endl;
cin>>choice2;
switch(choice2){
case 1:
cout<<"Distance Formula"<<endl;
cout<<endl;
cout<<"Enter first y point (y1)"<<endl;
cin>>y1;
cout<<endl;
cout<<"Enter second y point (y2)"<<endl;
cin>>y2;
cout<<endl;
cout<<"Enter first x point (x1)"<<endl;
cin>>x1;
cout<<endl;
cout<<"Enter second x point (x2)"<<endl;
cin>>x2;
cout<<"D=sqrt (x2-x1)+(y2-y1)";
cout<<endl;
cout<<endl;
cout<<"Distance ="<<sqrt((x2-x1)+(y2-y1))<<endl;
cout<<endl;
cout<<endl;
system("pause");
return 0;
case 2:
cout<<"AREA OF A CIRCLE"<<endl;
cout<<endl;
cout<<"Enter Radius"<<endl;
cin>>r;
cout<<endl;
cout<<endl;
cout<<"FORMULA PI X R^2";
cout<<endl;
cout<<endl;
cout<<"Area of Circle ="<<pi*(pow(r,2))<<endl;
cout<<endl;
cout<<endl;
system("pause");
return 0;
case 3:
cout<<"AREA OF A CIRCLE"<<endl;
cout<<endl;
cout<<"Enter Radius"<<endl;
cin>>r;
cout<<endl;
cout<<endl;
cout<<"FORMULA PI X R^2";
cout<<endl;
cout<<endl;
cout<<"Area of Circle ="<<pi*(pow(r,2))<<endl;
cout<<endl;
cout<<endl;
system("pause");
return 0;
}
}
}
해결책 2
주요 문제는 글로벌 변수가 y1 정의 된 함수와 충돌 할 수 있습니다 math.h (또는 cmath). 로컬로 변수를 main() 글로벌보다는 기능. 이를 통해 변수 이름이 기존 함수를 숨길 수 있으며 충돌을 피합니다.
편집 : 대체 솔루션은 이름을 바꾸는 것입니다 y1 예를 들어 다른 것에 Y1 (상류).
코드에는 몇 가지 다른 문제도 있습니다. 당신이 가진 두 곳에서 cout< 대신에 cout <<, 그리고 당신은 또한 세미콜론을 놓치고 있습니다.
다른 팁
업데이트:
보입니다 y0, y1 그리고 yn ~이다 POSIX의 일부로 지정됩니다 이 문서화 된 이유를 설명 할 것입니다. 씨 또는 C ++ 표준 :
y0 (), y1 () 및 yn () 함수는 각각 두 번째 종류의 주문 0, 1 및 n의 X의 베셀 함수를 계산해야합니다.
해결책 글로벌 네임 스페이스 오염 그렇습니다 자신의 네임 스페이스에 변수를 선언하십시오.
원래의:
당신은 가지고 있습니다 < 대신에 << 당신의 몇 가지 cout 예를 들어 여기에 전화 :
cout<"FORMULA L2+H2";
^
해야한다:
cout<<"FORMULA L2+H2";
^^
또한 clang 그리고 gcc, 나는 당신의 글로벌과 충돌하고 있습니다 y1 그리고 글로벌 y1 ~로부터 cmath 헤더는 이것을 만듭니다.
cout<<"Distance ="<<sqrt((x2-x1)+(y2-y1))<<endl;
^^
그리고 몇 가지 다른 줄이 끊어지면 내 해결책은 이름을 바꾸는 것이 었습니다. y1 그러나 더 나은 해결책은 글로벌을 사용하지 않는 것입니다.
