How can I concatenate object names with string or integer in java can anyone have an idea.

Button[] digitButtons = new Button[10];
for(int i = 0; i < 10; i  ) {
    final int buttonInd = i;
    Button btn0 i = new Button(Integer.toString(i));
    digitButtons[i] = btn0 i;
    digitButtons[i].setOnAction(new EventHandler<ActionEvent>() {
        @Override
        public void handle(ActionEvent e) {
            System.out.println("Button pressed "   ((Button) e.getSource()).getText());
            System.out.println("button clicked "   ((Control)e.getSource()).getId());
            lastClickedIndex = buttonInd;
        }
    });
}

CodePudding user response：

Put your buttons in a HashMap<String, Button>, and this way you could name your buttons and rename them as many times as you want. You cannot rename variables in runtime.

Here is an example:

// this will keep the variables this way: [ "btn01" -> buttonObject1, "btn02" -> buttonObject2 ...]
HashMap<String, Button> buttonHashMap = new HashMap<>();

for(int i = 0; i < 10; i  ) 
{
    final int buttonInd = i;
    String buttonName = "btn0"   i;
    Button buttonObject = new Button(Integer.toString(i));
    
    buttonHashMap.put(buttonName, buttonObject);

    // The .get(buttonName) gets the specific Button that you need!
    buttonHashMap.get(buttonName).setOnAction(new EventHandler<ActionEvent>() {
        @Override
        public void handle(ActionEvent e) {
            System.out.println("Button pressed "   ((Button) e.getSource()).getText());
            System.out.println("button clicked "   ((Control)e.getSource()).getId());
            lastClickedIndex = buttonInd;
        }
    });
}