c++ - 请求 “…”中属于非类类型 “…”的成员 “…”

This question already has answers here:

error: request for member '..' in '..' which is of non-class type

(9个答案)


7年前关闭。




我已经花了好几个小时试图找出我在做什么错，并且已经摆脱了大多数问题，但是当我尝试在main()中编译我的代码时，也会出现以下错误消息:

request for member "..." in "..." which is of non-class type "..."

对于我尝试在main()中调用的所有功能，它都会重复执行。问题是什么？我不知道我的错误在哪里。

我在Macbook上使用Terminal来编译代码。

这是我的主要功能:

//Program1.cpp
//Program1Math test function
#include "Program1Math.h"

int main()
{
  //Create a Program1Math object
  Program1Math myProgram1Math();

  myProgram1Math.setNumber1();
  myProgram1Math.setNumber2();

  myProgram1Math.displayMultiple();
  myProgram1Math.displaySine1();
  myProgram1Math.displayTangent1();
  myProgram1Math.displaySine2();
  myProgram1Math.displayTangent2();
}

这是该类的成员函数定义:

//Program1Math.cpp
//Program1Math member-function definitions.
#include <iostream>
#include <cmath>
#include "Program1Math.h"
using namespace std;

//constructor makes a Program1Math, adds an blank line
Program1Math::Program1Math()
{
  cout << "/n";
}

//function to assign the first integer to its appropriate location
void Program1Math::setNumber1()
{
  cout << "Please enter the first integer number /n";
  int numberSpot;
  cin >>numberSpot;
  static_cast<double>(numberSpot);
  number1 = numberSpot;
}

//function to assign the second integer to its appropriate location
void Program1Math::setNumber2()
{
  cout << "Please enter the second integer number /n";
  int numberSpot;
  cin >>numberSpot;
  static_cast<double>(numberSpot);
  number2 = numberSpot;
}

//function to find the sine value for a specified number
void Program1Math::calculateSine( double inputNumber )
{
  sineValue = sin( inputNumber );
}

//function to find the tangent value for a specified number
void Program1Math::calculateTangent( double inputNumber )
{
  tangentValue = tan( inputNumber );
}

//function to determine if the user-inputted numbers are multiples of each other
void Program1Math::calculateModulus()
{
  int number1Int = static_cast<int>(number1);
  int number2Int = static_cast<int>(number2);
  int modulusValue = number1Int % number2Int;
  if ( modulusValue == 0 )
    multiple = true;
  else
    multiple = false;
}

//function to display the whether the numbers are multiples or not
void Program1Math::displayMultiple()
{
  if( multiple == true )
    cout<< number1 << " is a multiple of " << number2 << "!/n";
  else
    cout<< number1 << "is not a multiple of " << number2 << "./n";
}

//function to display the sine value of the first number
void Program1Math::displaySine1()
{
  calculateSine( number1 );
  cout << "Sine(" << number1 << ") = " << sineValue << "/n";
}

//function to display the sine value of the second number
void Program1Math::displaySine2()
{
  calculateSine( number2 );
  cout << "Sine(" << number2 << ") = " << sineValue << "/n";
}

//function to display the tangent value of the first number
void Program1Math::displayTangent1()
{
  calculateTangent( number1 );
  cout << "Tan(" << number1 << ") = " << tangentValue << "/n";
}

//function to display the tangent value of the second number
void Program1Math::displayTangent2()
{
  calculateTangent( number2 );
  cout << "Tan(" << number2 << ") = " << tangentValue << "/n";
}

这是头文件:

#include <cmath>
using namespace std;

class Program1Math
{
 public:
  Program1Math();
  void setNumber1();
  void setNumber2();
  void calculateSine( double );
  void calculateTangent( double );
  void calculateModulus();
  void displayMultiple();
  void displaySine1();
  void displaySine2();
  void displayTangent1();
  void displayTangent2();
 private:
  double number1;
  double number2;
  double sineValue;
  double tangentValue;
  bool multiple;
};

最佳答案

Program1Math myProgram1Math();行被解释为返回myProgram1Math()的函数声明Program1Math；

只需使用

 Program1Math myProgram1Math;

仅当构造函数接受参数(不带默认参数)时才使用()。

编辑:您必须编译组成程序的所有源(.cpp)文件。
这将产生具有不同扩展名的同名目标文件(在Windows中，该文件是.obj，对于您来说是.o)。

之后，必须将所有这些.o -files与某些编译器提供的库链接到getcher上，以生成可执行程序。