Question

好的，所以这就是我需要的。我有一个if语句，如果它返回true，然后将文本添加到字符串，如果它是else，则将不同的文本添加到同一个字符串。继承我的代码：

 import java.awt.*;
 import java.util.*; 
 import javax.swing.*;
 import java.awt.event.*;

      public class theclock extends JFrame {
      theclock() {
         final JLabel timeField = new JLabel();
         timeField.setFont(new Font("sansserif", Font.PLAIN, 20));

         Container content = this.getContentPane();
         content.setLayout(new FlowLayout());
         content.add(timeField); 

         setTitle("Norway");
         setSize(150,70);

         javax.swing.Timer t = new javax.swing.Timer(1000,new ActionListener() {
         public void actionPerformed(ActionEvent e) {
             Calendar cal = new GregorianCalendar();
             String a = ""; //empty string that I want to add text to
             String h = String.valueOf(cal.get(Calendar.HOUR)+8); //I know its not the easiest way to add 8 hours, but im experimenting.
                int i = Integer.parseInt(h);
                    if (i>12)
                    {
                          i=i-12;
                          a = "A.M"; //what to add to the string if it is true
                    }
                    else
                    {
                         i=i; //haven't applied myself to this part yet, so i know its probably wrong, but its just a place holder
                         a = "P.M"; //for when it is else, i should say pm.
                    }
             String m = String.valueOf(cal.get(Calendar.MINUTE));
             String s = String.valueOf(cal.get(Calendar.SECOND));
             timeField.setText("" + i + ":" + m + ":" + s + " " + a); //where the string is shown.
             }
         });
         t.start(); 
     }
     public static void main(String[] args) {
         JFrame clock = new theclock();
         clock.setVisible(true);
     }
 }

Answer 1

如果您需要附加到可以使用的字符串：

if (i>12)
{
    i=i-12;
    a = a + "A.M"; //appends 'A.M' to the string if the string already has a value
} 
else 
{
    i=i;
    a = a + "P.M"; //appends 'P.M' to the string if the string already has a value
}

如果if语句返回true，则将文本写入字符串，如果else则返回不同的文本

1 个答案: