compiler-warning-level-3-c4287.md

description	title	ms.date	f1_keywords	helpviewer_keywords
Learn more about: Compiler Warning (level 3, off) C4287	Compiler Warning (level 3, off) C4287	11/04/2016	C4287	C4287

Compiler Warning (level 3, off) C4287

'operator' : unsigned/negative constant mismatch

An unsigned variable was used in an operation with a negative number.

This warning is off by default. For more information, see Compiler Warnings That Are Off by Default.

Example

The following sample generates C4287:

// C4287.cpp
// compile with: /W3
#pragma warning(default : 4287)
#include <stdio.h>

int main()
{
    unsigned int u = 1;
    if (u < -1)   // C4287
        printf_s("u LT -1");
    else
        printf_s("u !LT -1");
    return 0;
}