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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. 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("\n%d",arr[0][1,0]);   // C4709