"<<" operator overloading

Code:

---

#include <iostream>
#include <cstring>
using namespace std;

class Matrix{
        private:
                int i,j;
        public:
                int mat[5][5];
                Matrix(int x,int y,int p){
                        for(i=0;i<x;i++)for(j=0;j<y;j++)mat[i][j]=p;
                }
};
int main(){
        Matrix m(5,5,1);
        cout << m(2,2) << endl;
        return 0;
}

---

Hello all ... i want to show the element of mat[2][2] using cout (<<) operator overloading.How can i do this ??

Thanks in advance :)

Hi,
As I understand your question you don't need any operater overloading. Just use a method to get mat[i][j] value. you can pass the i & j as parameters.

Shanuka

You're going about this class the wrong way. The mat array should be private and you should overload the () operator instead to return the value at the specified index.

C++ [] array operator with multiple arguments? - Stack Overflow

@ Shanuka : I dont want to change "cout << m(2,2) << endl" ... so i need operator overloading.
@ Memloop : would you please give an example ??

Check out the link above.

Google functors.

Thanks for your help :)
need some help again

I have initialized a 3x4 matrix using "Matrix b(3,3)".Here 'b' is an object of Matrix class.now i want to use "b(2,2)=1" this statement to place 1 at that matrix's [2][2] index.how can i do this ??

example:

Quote:

---

Matrix b(3,3)
0 0 0
0 0 0
0 0 0

b(2,2)=1
0 0 0
0 1 0
0 0 0

---

Thanks in advance :)

Make operator() return a reference to int.

BTW, in case you haven't realized, this is a very awkward way of doing things.

I'm guessing you are used to languages like Matlab where matrix indexing is done by (). The equivalent for that in C++ is [].

Code:

---


                double operator()(size_t i,size_t j)const
                {
                        if(i>=0 && i<length_of_row && j>=0 && j<length_of_col)        return _Matrix[i][j];
                        else throw MatrixError(1);
                       
                }

---

i am using this code portion to print an element of a specified index ...
cout << b(2,2) << endl will work ...

what about b(2,2)=1 ??

Add a & before operator.

Quote:

---

Originally Posted by cyberfish

Add a & before operator.

---

That, and make a non-const version of the function.