您好,我正在尝试重载 << 运算符以便将矩阵输出为表格。我已经开始实现并完成了它,但我不确定我是否做对了,因为我遇到了对我来说没有意义的错误。这是我第一次重载 << 所以我不确定我是否做对了。请帮忙。
错误(已编辑):
In file included from MatrixTester.cpp:3:
Matrix.h:16: error: expected ‘;’ before ‘operator’
In file included from MatrixTester.cpp:4:
Matrix.cpp:132: error: ‘std::ostream& Matrix::operator<<(std::ostream&, const Matrix&)’ must take exactly one argument
MatrixTester.cpp: In function ‘int main()’:
MatrixTester.cpp:15: error: no match for ‘operator<<’ in ‘std::cout << matrix’
/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../include/c++/4.4.7/ostream:108: note: candidates are: std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator<<(std::basic_ostream<_CharT, _Traits>& (.....
我的 MatrixTester.cpp:
#include "Matrix.h"
#include "Matrix.cpp"
#include<iostream>
#include<vector>
using namespace std;
int main(){
int row,column;
cout << "Enter number of rows: ";
cin >> row;
cout << "Enter number of column: ";
cin >> column;
Matrix matrix(row,column);
cout<<matrix;
vector<int> rowVec;
vector<int> colVec;
bool cont = true;
do{
cout << "Enter column index: ";
int index;
cin >> index;
for(int i = 0; i < row; i++){
cout << "Enter an integer: ";
int num;
cin >> num;
colVec.push_back(num);
}
if (matrix.setColumn(colVec,index) == false){
cout << "Unable to modify matrix: Index might be out of bounds " << endl;
}else{
cont = false;
}
}while(cont == true);
cout<<matrix;
cout << "Enter row index: ";
int index;
cin >> index;
rowVec = matrix.getRow(index);
for (int i =0;i<rowVec.size();i++){
cout << rowVec[i] << " ";
}
cout << endl;
double avg = matrix.average();
cout<<"Average: " <<avg<<endl;
Matrix m2(rowVec.size(), colVec.size());
rowVec = matrix.getRow(1);
for (int i=0; i <= row-1; i++){
cout <<"for l" <<endl;
m2.setRow(rowVec,i);
}
cout <<"Adding..." <<endl;
Matrix m3(row,column);
m3 = matrix + m2;
cout<<m3;
cout <<"Subtract..." <<endl;
m3 = matrix - m2;
cout<<m3;
cout <<"Multiply..." <<endl;
m3 = matrix * m2;
cout<<m3;
}
矩阵.h
#ifndef MATRIX_H
#define MATRIX_H
#include<vector>
using namespace std;
class Matrix{
public:
Matrix();
Matrix(int r, int c);
bool setRow(vector<int> row, int r);
bool setColumn(vector<int> col, int c);
vector<int> getRow(int index);
vector<int> getCol(int index);
void indentityMatrix();
ostream& Matrix operator<<(ostream& out, const Matrix& m);
double average();
Matrix operator+(Matrix m);
Matrix operator-(Matrix m);
Matrix operator*(Matrix m);
Matrix operator/(Matrix m);
private:
int row, column;
vector< vector<int> > matrix;
};
#endif
在 Matrix.cpp 中重载运算符<<(已编辑)
ostream& Matrix::operator<<(ostream& out, const Matrix& m){
vector<int> vecRow;
for (int i = 0; i < row; i++){
vecRow = m.getRow(i);
for (int j = 0; j < row; j++){
out << vecRow[j];
out <<"\t";
}
out << endl;
}
return out;
}
我仍然收到错误
最佳答案
错误的原因是你有#include "Matrix.cpp"
在你的代码中。它本身是错误的,但在这种情况下它也会导致“不完整类型”错误,因为它包含在 <iostream>
之前。标题。
你永远不需要 #include
一个.cpp文件。如果您这样做是为了解决链接问题,因为运算符 <<
已经丢失,修复它的正确方法是在同一个命令上编译你的 cpp 文件,单独编译它们而不链接然后链接,或者将它们作为你的 IDE 项目的单独项目包含(如果你使用的是开发环境) .
请注意,您正在传递 Matrix
按值(value)给运营商。这是次优的,因为您的整个矩阵只是为了打印而被复制。通常,您应该将正在打印的项目传递给运算符(operator) <<
通过不断的引用:
// This goes into the Matrix.h header:
friend std::ostream & operator<<(std::ostream &out, const Matrix& p);
// This goes into Matrix.cpp implementation:
ostream& operator<<(ostream& out, const Matrix& m) {
...
}
编辑(感谢您的提示,Mooing Duck!)
关于c++ - 在 C++ 中将 << 运算符重载到输出矩阵,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/26720245/