CODEWITHSUNDEEP
java
user9076017
user9076017

Reputation:

In this code the Runnable is not instantiated. Why?

// Runnable cannot instantiate
public class Thread4 {
    public static void main(String[] args) {
        Thread t1 = new Thread(new Runnable());
    }
}

//Runnable cannot instantiate

Why? Although in the other program it's instantiating with the same code.

Upvotes: 0

Views: 1312

Answers (2)

UmaShankar Chaurasiya
UmaShankar Chaurasiya

Reputation: 111

Directly you can't pass new Runnable() inside new Thread(). You need to create an implemented class (for example : MyTestRunnable.java) which implement Runnable Interface and pass new MyTestRunnable() in new Thread().

public class MyTestRunnable implements Runnable {
    public void run(){
       System.out.println(" .... ");
    }
  }


public class Thread4 {
    public static void main(String[] args) {
       Thread t1 = new Thread(new MyTestRunnable());
    }
}

Upvotes: 2

Eran
Eran

Reputation: 393781

Runnable is an interface, not a class. In order to instantiate it, you must supply a class that implements the interface (or a lambda expression or method reference if you are using Java 8 or later).

For example:

Thread t1 = new Thread(new Runnable() {public void run() {}});

Here I defined an anonymous class that implements Runnable and created an instance of that class.

Upvotes: 3

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