Question

以下是我的错误结果中使用的所有.cpp和.h文件。它们是我之前看到并修复的错误，但我不明白为什么我会收到这些错误，它不会为代码制作正确的语法。

shape.h

#ifndef SHAPE_H
#define SHAPE_H
#include <iostream>
#include <math.h>
#include <cmath>
#include <cstring>
#include <string>
#include <algorithm>
#include <iomanip>
#include <stdlib.h>

using std::cout; using std::cerr; using std::endl;
using std::string;
    class Shape{
      public:
    Shape(const string&)  { } //default constructor
    virtual void print() const;
    virtual double get_area() const;
    virtual ~Shape();
      private:
    string color;
    };
#endif

shape.cpp

#include "shape.h"
using std::cout; using std::cerr; using std::endl;
using std::string;
void Shape::print() const{
cout << color << endl; }
Shape::Shape(const string& color1):color(color1)
{/*color = color1;*/ }
Shape::~Shape()
{ }

circle.h

#ifndef CIRCLE_H
#define CIRCLE_H
#include <iostream>
#include <math.h>
#include <cmath>
#include <cstring>
#include <string>
#include <algorithm>
#include <iomanip>
#include <stdlib.h>
#include <vector>
#include "shape.h"
using namespace std;
using std::cout; using std::cerr; using std::endl;
using std::string; using std::vector;
class Circle : public Shape{
  public:
  Circle(const string& , int); 
virtual void print() const;
virtual double get_area() const;
  private:
int radius;
};
#endif

circle.cpp

 #include "circle.h"
using std::cout; using std::cerr; using std::endl;
using std::string;
Circle::Circle(const string& color1,int newRadius):Shape(color1),radius(newRadius) {}

double Circle::get_area() const{
double area;
area = M_PI * (pow(radius,2) );
return area;
}

void Circle::print() const{
cout << "Circle: " <<
     << color << " circle, "
     << "radius " << radius << ", "
     << "area " << get_area() << endl;
}

主

#include <iostream>
#include "shape.h"
#include "circle.h"
#include <vector>
using std::vector; using std::string;
using namespace std;
int main{

    vector<Shape *> shape1(1);
    shape1[0] = new Circle("Green",20);

/*
for(int i = 0; i < arr; i++ )
i.print();

for(int i = 0; i < arr; i++ )
delete [] arr;
*/
 return 0;

错误：

    assign9.cpp:9:17: error: expected primary-expression before ‘shape1’
 vector<Shape *> shape1(1);
                 ^
assign9.cpp:9:17: error: expected ‘}’ before ‘shape1’
assign9.cpp:9:17: error: expected ‘,’ or ‘;’ before ‘shape1’
assign9.cpp:10:1: error: ‘shape1’ does not name a type
 shape1[0] = new Circle("Green",20);
 ^
assign9.cpp:19:2: error: expected unqualified-id before ‘return’
  return 0;
  ^
assign9.cpp:20:1: error: expected declaration before ‘}’ token
 }

^

我不明白这些错误是如何发生的，即使我的TA也无法弄明白。我感谢任何反馈。感谢

Answer 1

Cirlce而不是Circle。

string而不是std :: string。

另外，Circle的构造函数应该更好 Circle :: Circle（const string＆amp; color1，int newRadius）：Shape（color1），radius（newRadius）{}

（在构造函数中而不是在括号中初始化所有内容）。

简单的编译错误但没有意义

1 个答案: