Java - Iterate through an array everytime a button is pressed

Question

I would like to iterate through a list every time a button is pressed, using JButton, JTextField and event's ActionListener. So every time the "next" button is pressed the next item in the array should be displayed in a JTextField. I have already created the getters, setters and constructor, it's literally only the following piece I'm having trouble with.

@Override
     public void actionPerformed(ActionEvent evt){
     Object source = evt.getSource();

     String[] item = getThing();

     for(int i = 0; i < 3; i ++){
         String currentI = item[i];
     }
     if(source.equals(btnNxt)){
         txtDisplayField.setText(currentI);
     }
}

In the if statement I receive an error "Cannot find symbol", referring to currentI.

meskobalazs · Accepted Answer · 2015-09-21 12:49:40Z

4

The currentI variable went out of scope at the end of the loop. You should declare it outside of the for loop.

By the way, the code still won't work properly, because you set the value to the last item of the array every time. You should step only once, and if you are at the last item, jump to the first one.

answered Sep 21, 2015 at 12:49

meskobalazs

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Comments

Mena · Accepted Answer · 2015-09-21 12:50:01Z

1

You're initializing your currentI String within your for loop's scope.

The variable is therefore inaccessible outside your for loop.

Move your equality check and assignment inside the loop.

for(int i = 0; i < 3; i ++){
    String currentI = item[i];

    if(source.equals(btnNxt)){
        txtDisplayField.setText(currentI);
        // stop iteration as you already found a match
        break;
    }
}

answered Sep 21, 2015 at 12:50

Mena

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Comments

CoderBrain · Accepted Answer · 2015-09-21 13:08:29Z

0

I don't see why you need a for loop at all.

Simply :

int ctr = 0;
public void actionPerformed(ActionEvent evt){
  ctr++;
  if(ctr<item.length)
    txtDisplayField.setText(iter[ctr]);
}

That should solve your problem

answered Sep 21, 2015 at 13:08

CoderBrain

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