// app3_1,簡單的實例 
public class app3_1
{
   public static void main(String args[])
   {
      int num=3;	// 聲明num為整數，并賦值為3
      char ch='A';	// 聲明ch為字符變量，并賦值為'A'
      System.out.println(num + " is an integer");
      System.out.println(ch + " is a character");
   }
}