Java Programming - Threads - Discussion

Discussion Forum : Threads - Finding the output (Q.No. 18)
What will be the output of the program?
class MyThread extends Thread 
    public static void main(String [] args) 
        MyThread t = new MyThread();
        Thread x = new Thread(t);
        x.start(); /* Line 7 */
    public void run() 
        for(int i = 0; i < 3; ++i) 
            System.out.print(i + "..");
Compilation fails.
Answer: Option

The thread MyThread will start and loop three times (from 0 to 2).

Option A is incorrect because the Thread class implements the Runnable interface; therefore, in line 7, Thread can take an object of type Thread as an argument in the constructor.

Option B and C are incorrect because the variable i in the for loop starts with a value of 0 and ends with a value of 2.

10 comments Page 1 of 1.

Neha singh chauhan said:   8 years ago
Since the value of x < 4

Therefore, it will print 0 1 2 3 only.

Anonymous said:   8 years ago
Guys the class mythread doesn't implement the runnable here in the code it extends the thread class.

Ashu said:   9 years ago
In main method the method start is called run is not even called then. How is D correct?

John said:   9 years ago
Is it possible to construct a Thread with an instance of Thread as an argument?

Png said:   9 years ago
Read basics of for loop. @Rahul is correct.

Kamlesh Choubey said:   9 years ago
After condition check control always goes to body part directly and after body execution it increments the value.

Harsh said:   1 decade ago
But the thing is before printing the value of i, it is incremented because of ++i. So according to me the answer is B.

Rahul said:   1 decade ago
No,I disagree with @Akhay because here the control is as follows:

1. Goes to int i=0;
2. Then to i<3;
3. Body part will be executed.
4. Finally ++i will be executed.

So, i++ or ++i both will give same result i.e 0..1..2.

Akshay said:   1 decade ago
Yes, agree with Neha. As it is ++i it will print from 1 and output will be 1. 2.

Neha said:   1 decade ago
But in loop there is ++i, so value of I ll be increase before it print. Thus in my opinion the ans is B.

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