20209/29

今天学习随机数，和JOptionPane的一些使用

//An addition program 

import javax.swing.JOptionPane;  // import class JOptionPane

public class Addition {
public static void main( String args[] )
{
   String firstNumber,   // first string entered by user
          secondNumber;  // second string entered by user
   int number1,          // first number to add
       number2,          // second number to add
       sum;              // sum of number1 and number2

   // read in first number from user as a string
   firstNumber =
      JOptionPane.showInputDialog( "Enter first integer" );

   // read in second number from user as a string
   secondNumber =
      JOptionPane.showInputDialog( "Enter second integer" );

   // convert numbers from type String to type int
   number1 = Integer.parseInt( firstNumber ); 
   number2 = Integer.parseInt( secondNumber );

   // add the numbers
   sum = number1 + number2;

   // display the results
   JOptionPane.showMessageDialog(
      null, "The sum is " + sum, "Results",
      JOptionPane.PLAIN_MESSAGE );

   System.exit( 0 );   // terminate the program
}
}

 

//JOptionPane方便用户提供值时弹出标准对话框；JOptionPane.showInputDialog窗口显示，读取数据用字符串类型；
//Integer.parseInt()是把()里的内容转换成整数
//showConfirmDialog()：确认对话框
//showInputDialog()：输入对话框
//showMessageDialog()：消息对话框
//showOptionDialog()：选择对话框

二.随机数不重复还有什么简单方法

三.动手动脑