这里的语法是什么？

Question

Im writing calculator in java Swing and having issue with syntax:

https://imgur.com/gYtQuTC cannot resolve symbol dotButtonText is fixible with initializing before dotButton method,but it still asking for ")" ";"

  dotButton.addActionListener(new ActionListener() {
  @Override
  public void actionPerformed(ActionEvent e) {
    if(TextFieldDisplay.getText().equals("")){
      TextFieldDisplay.setText("0");
    }
    else if (TextFieldDisplay.getText().contains(".")){
      dotButton.setEnabled(false);
    }
    else
      (
              (String dotButtonText = TextFieldDisplay.getText()+dotButton.getText();
    TextFieldDisplay.setText(dotButtonText);

  }
});

I want to variable dotButtonText to take default value of "" if not pressed,and ".0" if button is pressed

Answer 1

1. You used ( instead of a curly braces { for your else block.
2. You have an extra ( at the beggining of your statement.

Remove those, and it will work fine:

else
{
    String dotButtonText = TextFieldDisplay.getText()+dotButton.getText();
    TextFieldDisplay.setText(dotButtonText);
}

Answer 2

else {
   //";"expected  ")"expected  ")"expected after string
   // (String dotButtonText = TextFieldDisplay.getText()+dotButton.getText();
   TextFieldDisplay.setText(dotButtonText);
}

You have added an extra ( . Remove it and everything will work fine.