java - Why should I use Runnable instead of Thread? -

this question has answer here:

• “implements runnable” vs. “extends thread” 37 answers

i learn theory thread. , there thread , runnable.

class extends thread{     public void run(){             while(true) {                 system.out.println("hi");             }                    }     } 

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class b implements runnable{     public void run(){         system.out.println("hi");     } } 

thread rich api, why use runnable instead of thread?

thanks.

1. java doesn't support multiple inheritance, means can extend 1 java class, once extended thread class lost chance , cannot extend(inherit) class in java.

2. in oop extending class means adding new functionality, modifying or improve behaviors. if not making modification on thread, use runnable interface instead.

3. implementing runnable makes class more flexible(you can implement more 1 interface).