磅转为千克

import javax.swing.JOptionPane;
public class Weight {
    public static void main(String[] args){
        String input = JOptionPane.showInputDialog(null,"请输入磅数：","输入框",JOptionPane.QUESTION_MESSAGE);
        double pounds = Double.parseDouble(input);
        System.out.println(pounds + " pounds is " + pounds * 0.454 + " kilograms");
    }

}