java - android app crashes when starting/stopping media -


i writing small practice app plays sound clip when button tapped. in previous code, amounts creation of mediaplayer object , call mp.start() start audio. works, same button play when no sound playing yet. if sound playing, stop audio. play/stop button. tried using following code: ``` 

public class mainactivity extends activity { mediaplayer mp;       @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);      }      public void gobuttonclicked(view v) { if(mp == null) {     mediaplayer mp = mediaplayer.create(getapplicationcontext(), r.raw.wordt); }     if(mp.isplaying()) { mp.stop(); mp.release(); }      else { mp.start();     } } } ```

however when run app, app crashes when tap button. did go wrong?

just change code this,

public void gobuttonclicked(view v) {     if(mp == null) {         mp = mediaplayer.create(getapplicationcontext(), r.raw.wordt);     }     .... }

what happens here is, mediaplayer mp = ... means creating local variable inside if condition. still field variable null. , when app executes second if condition, throws nullpointerexception.


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