Threads

[Army]

Single thread means just a normal program right? It's just normal. ie

class HelloWorld{
public static void main(String [] args){
System.out.println("hi");
}
}

But multiple is different how?



Is this an example of multiplethreading?

public class Threading extends Thread {
	public void run(){
		for(int i = 0; i <= 30; i++){
			System.out.println(i);
		}
	}
	public static void main(String [] args){
		new Threading().start();
	}
}

[KevinWorkman]

This is the first result for googling "java threading": Lesson: Concurrency (The Java™ Tutorials > Essential Classes)

[Army]

I know, I was already looking at it. Is there any difference in the first one and the second one that i posted?

[KevinWorkman]

I know, I was already looking at it. Is there any difference in the first one and the second one that i posted?

What happens when you run each? To further demonstrate threading, you might try something more like this (not tested, may contain compiler errors):

public class Threading extends Thread {
    int n;
    public Threading(int n){
        this.n = n;
    }

    public void run(){
        for(int i = 0; i <= 1000; i++){
            System.out.println("Thread " + n + " executing.");
            System.out.println(i);
            System.out.println("Thread " + n + " done executing. Sleeping now...");
            Thread.sleep(Math.random() * 5000);
        }
    }
    public static void main(String [] args){
        new Threading(1).start();
        new Threading(2).start();
        new Threading(3).start();
    }
}

[Army]

Write a program to print the even numbers and the odd numbers between 0 and 30 using a single thread and then again using multiple threads.
^That is the question I was asked. The second code is the one I thought had implemented multi-threading.

[Army]

public class Threading extends Thread {
    int n;
    public Threading(int n){
        this.n = n;
    }
 
    public void run(){
        for(int i = 0; i <= 30; i++){
            System.out.println("Thread " + n + " starting.");
            System.out.println(i);
            System.out.println("Thread " + n + " done starting. Sleeping now...");
            try {
				Thread.sleep(5000);
			} catch (InterruptedException e) {
				
				System.out.println("Thread " + n + "was not finished.");
			}
        }
    }
    public static void main(String [] args){
        new Threading(1).start();
        new Threading(2).start();
        new Threading(3).start();
    }
}

After some tweaking I did this, but then it does 3 threads all printing the same thing. How would I start to make it where as if one thread is printing the same number then the thread with the same number would sleep.

[KevinWorkman]

Write a program to print the even numbers and the odd numbers between 0 and 30 using a single thread and then again using multiple threads.
^That is the question I was asked. The second code is the one I thought had implemented multi-threading.

By that definition, I guess you technically accomplished the goal. But I would expect something is missing from the description. Either that or it's a bit of a lame example of threading, imho.

[KevinWorkman]

After some tweaking I did this, but then it does 3 threads all printing the same thing. How would I start to make it where as if one thread is printing the same number then the thread with the same number would sleep.

I meant that as a basic example of what threads do, not as an answer to your assignment. Did you read through the tutorial I linked?