Sonir:
Your program is one
thread,which assigns the value to x.
When you create a new instance of thread and call it's start method, that starts a new thread. The run() method gets executed by this new thread.
If the new thread is gets to execute before the println statement, then the value of x will be 10.
If the new thread has not had a chance to run, then the values of x will be 5.
Based only on this code, we can not know whether or not the new thread will start running immediately and finish before the println statement is executed. It depends on the operating system and how it implements thread scheduling, and other threads running at the same time as this program etc.
Therefore it is not possible to say what value of x will be printed .
HTH