.compiled but runtime error.Head First Java Chapter 11, example on page 346

[chaitanya ashtekar]

>compiles but does not run.i have tried changing `args[0]`to `args[1]`
still the output of cmd is this:
H:\jp>java ma
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
at ma.main(ma.java:7)

 import javax.sound.midi.*;
    public class ma{
        public static void main(String[] args){
	ma app =new ma();
	int instrument=Integer.parseInt(args[0]);
	app.play(instrument);}
        public void play(int instrument){
	try{
		Sequencer player=MidiSystem.getSequencer();
		player.open();
		Sequence seq=new Sequence(Sequence.PPQ,4);
		Track track=seq.createTrack();

		MidiEvent event=null;

		ShortMessage first=new ShortMessage();
		first.setMessage(192,1,instrument,0);
		MidiEvent changeInstrument=new MidiEvent(first,1);
		track.add(changeInstrument);

		ShortMessage a=new ShortMessage();
		a.setMessage(144,1,44,100);
		MidiEvent noteOn=new MidiEvent(a,1);
		track.add(noteOn);

		ShortMessage b=new ShortMessage();
		b.setMessage(128,1,44,100);
		MidiEvent noteOff=new MidiEvent(b,16);
		track.add(noteOff);

		player.setSequence(seq);
		player.start();

	  }catch(Exception ex){ex.printStackTrace();}}
         

[Henry Wong]

chaitanya ashtekar wrote: >compiles but does not run.i have tried changing `args[0]`to `args[1]`
still the output of cmd is this:
H:\jp>java ma
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
at ma.main(ma.java:7)

Well, since you didn't pass any actual parameters to the program, there isn't an args[0]. And likewise, there isn't an args[1] either.

Henry

[chaitanya ashtekar]

but i have written it exactly as written on Head First Java Chapter 11, example on page 346..

[chaitanya ashtekar]

Henry Wong wrote:

chaitanya ashtekar wrote: >compiles but does not run.i have tried changing `args[0]`to `args[1]`
still the output of cmd is this:
H:\jp>java ma
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
at ma.main(ma.java:7)

Well, since you didn't pass any actual parameters to the program, there isn't an args[0]. And likewise, there isn't an args[1] either.

Henry

okay.thank you.got what you meant.i did not pass any parameters in cmd