# Compiler Warning (level 4) CS0429

Unreachable expression code detected

This error occurs whenever part of an expression in your code is unreachable. In the following example, the condition false && myTest() meets this criteria because the myTest() method will never get evaluated due to the fact that the left side of the && operation is always false. As soon as the && operator evaluates the false statement as false, it stops the evaluation, and will never evaluate the right side.

## Example

The following code generates CS0429.

// CS0429.cs
public class cs0429
{
public static void Main()
{
if (false && myTest())  // CS0429
// Try the following line instead:
// if (true && myTest())
{
}
else
{
int i = 0;
i++;
}
}

static bool myTest() { return true; }
}