Compiler Warning (level 4) C4709

comma operator within array index expression

When a comma occurs in an array index expression, the compiler uses the value after the last comma.

Example

The following sample generates C4709:

// C4709.cpp
// compile with: /W4
#include <stdio.h>

int main()
{
    int arr[2][2];
    arr[0][0] = 10;
    arr[0][1] = 11;

    // Prints 10, not 11
    printf_s("\n%d",arr[0][1,0]);   // C4709
}