1 package debug;
 2 
 3 class Demo {
 4     /*
 5      * 定义八种基本数据类型，如下
 6      */
 7     
 8     public static void main(String[] args) {
 9         //define  char type
10         char a = '1';     //字符类型用单引号
11         System.out.println(a);
12         
13         //define string type
14         String text = "Hello world";  //字符串类型用双引号
15         System.out.println(text);
16         
17         //define float type
18         float f = 1.03F;   //单精度浮点类型后面必须要带上F或者f，默认用F
19         System.out.println(f);
20         
21         //define double type
22         double d = 1.345;  //浮点类型默认为双精度，所以如果定义的是doule类型，后面就不需要再带上F
23         System.out.println(d);
24         
25         //define short type
26         short s = 100;
27         System.out.println(s);
28         
29         //define int type
30         int i = 101;
31         System.out.println(i);
32         
33         //define long type
34         long l = 10000000000L; //定义长整型后面必须要带上L或者l，默认用L
35         System.out.println(l);
36         
37         //define byte type
38         byte a1 = 102;
39         System.out.println(a1);
40         
41         //define boolean
42         boolean b = false;
43         System.out.println(b);
44         
45         
46     }
47     
48 }

1 1
2 Hello world
3 1.03
4 1.345
5 100
6 101
7 10000000000
8 102
9 false