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C++
```#include<iostream.h>
#include<conio.h>
class matrix
{
public:
int a[3][3];
void getdata()
{
for(int i=1;i<=3;i++)
{
for(int j=1;j<=3;j++)
{
cout<<"Enter numbers for ["<<i<<"]["<<j<<"]";
cin>>a[i][j];
}
}
}
void putdata()
{
for(int i=1;i<=3;i++)
{
for(int j=1;j<=3;j++)
{
cout<<a[i][j];
}
cout<<endl;
}
}
};
{     //  matrix temp;
int a,i,j;
for(i=1;i<=3;i++)
{      a[3][3]=0;
for(j=1;j<=3;j++)
{
//	temp.a[i][j]=x.a[i][j]+y.a[i][j];
cout<<m1.a[i][j]+m2.a[i][j];
}
cout<<endl;
}
//   return temp;
}
int main()
{
clrscr();
matrix m1,m2,m3;
m1.getdata();
m2.getdata();
m3.putdata();
getch();
return 0;
}```

What I have tried:

i have tried all the options and tried mostly all the website for the answer.
Posted
Updated 27-Apr-17 0:27am
v2

## Solution 1

With C/C++ array indexes are zero based. You have an array `a[3][3]`. So the allowed indexes are in the range from 0 to 2.

Change all your loops to use these indexes:
```for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
/* ... */
}
}```

## Solution 2

C++
```matrix addMatrix(const matrix & m1, const matrix & m2)
{
matrix r;
for (int i=0; i<3; ++i)
for(j=0; j<3; ++j)
r.a[i][j] = m1.a[i][j] + m2.a[i][j];
return r;
}```

Another option would be `+` operator overloading, see operator overloading - cppreference.com[^].

## Solution 3

When you don't understand what your code is doing or why it does what it does, the answer is debugger.
Use the debugger to see what your code is doing. Just set a breakpoint and see your code performing, the debugger allow you to execute lines 1 by 1 and to inspect variables as it execute, it is an incredible learning tool.

Debugger - Wikipedia, the free encyclopedia[^]
Mastering Debugging in Visual Studio 2010 - A Beginner's Guide[^]
Basic Debugging with Visual Studio 2010 - YouTube[^]
The debugger is here to show you what your code is doing and your task is to compare with what it should do.
There is no magic in the debugger, it don't find bugs, it just help you to. When the code don't do what is expected, you are close to a bug.