java - Difference between running and starting a thread -

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• what's difference between thread start() , runnable run() 14 answers

i don't understand difference between starting , running thread, tested both methods , outputs same result, first used combination of run() , start on same thread , did same function follows:

public class testrunandstart implements runnable { public void run() {     system.out.println("running"); } public static void main(string[] args) {      thread t = new thread(new testrunandstart());      t.run();      t.run();      t.start();  } 

}

the output is:

running running running 

then saw javadoc of run() method said that: if thread constructed using separate runnable run object, runnable object's run method called; otherwise, method nothing , returns tried use run() method without separate runnable follows :

public class testrun extends thread { public void run(){     system.out.println("running normal thread"); } public static void main(string[]args){     testrun tr=new testrun();     tr.run();    }  } 

and executes run() method , prints running normal thread although it's constructed without separate runnable! what's main difference between 2 methods

thread.run() not spawn new thread whereas thread.start() does, i.e thread.run runs on same thread of caller whereas thread.start() creates new thread on task run.