Threads Question

[Mohit G Gupta]

scjptest.com

public class Cruiser implements Runnable {
    
    public void run() {
        System.out.print("go");
    }
    
    public static void main(String arg[]) {
        Thread t = new Thread(new Cruiser());
        t.run();
        t.run();
        t.start();
    }
}

A) Compilation fails.
B) An exception is thrown at runtime.
C) "go" is printed
D) "gogogo" is printed
E) "gogo" is printed
Answer: D

i think output should be c) as t.run() would call run method of Thread class

[Deepak Bala]

Did you run this ? What is the difference between the run() and start() methods ?

[Mohit G Gupta]

we have not defined any run method for thread class.so
t.run();
would do nothing

[Jesper de Jong]

Where did you copy this question from? Please remember that you are required to QuoteYourSources on JavaRanch whenever you copy a question from a book, mock exam or other source.

What do you mean with "from SCJP TEST"? Is this from the real, actual exam? Are you aware that you are not allowed to copy the content of the real exam?

[Trivikram Kamat]

mohitkumar gupta wrote:
think output should be c) as t.run() would call run method of Thread class

If the Thread whose run() method is called was constructed using separate Runnable object, then that Runnable object's run method is called. Otherwise, method does nothing and returns. (from Javadocs)