Question

While loking up “dead code” thread here
dead code warning in eclipse

I tried the following simple java code:

public class Test2
{
    public static void main(String[] args)
    {
        int x = 0;        
        while(false)
        {                        
            x=4;
        }
    }
}  

which correctly throws a compile time error

C:\Documents and Settings\user\Desktop\Test2.java:7: unreachable
statement
        {                        
        ^ 1 error

I tweaked the code very slightly to this:

public class Test2
{
    public static void main(String[] args)
    {
        int x =0;        
        while(true)
        {                        
            x=4;
        }
    }
}    

and it compiles just fine.

Is there a reason, why this compiles fine?

logically both should cause an infiniteloop and should both cause compile time error.

Am I doing something wrong?

Answer 1

logically both should cause an infiniteloop

Not quite: while(false) never enters the loop.

Also, the compiler doesn’t warn about infinite loops – you may actually want one:

while(true) {
    // poll some queue for work
    // if work found do it
    // else sleep 1 second
}