1 public class Chapter3 {
2
3 static int times=3;//成员变量
4
5 public static void main(String[] args){
6
7 byte mybyte=124;
8 short myshort=32564;
9 int myint=45784612;
10 long mylong=2343523444L;
11 long result=mybyte+myshort+myint+mylong;
12 System.out.println("结果为:"+result);
13
14
15 float f=3.14f;//不加f会报错
16 System.out.println(f);
17 char word='d',word2='@';
18 int p=23045,p2=41;
19 System.out.println("d在Unicode表中的顺序位置是:"+(int)word);
20 System.out.println("@在Unicode表中的顺序位置是:"+(int)word2);
21 System.out.println("Unicode表中23045位是:"+(char)p);
22 System.out.println("Unicode表中45213位是::"+(char)p2);
23
24 char c1='\\';
25 char c2='\u2605';
26 System.out.println(c1);
27 System.out.println(c2);
28
29 boolean b=false;
30 System.out.println(b);
31
32 final double PI;//局部终态变量
33 PI=3.141592654;
34 //常量在整个程序中只能被赋值一次
35 //PI=3.14;
36 System.out.println(PI);
37
38 System.out.println(times);
39 int times=4;
40 System.out.println(times);
41
42 int i=1;
43 System.out.println(i+(i++)+(++i));
44
45
46 //byte<short<int<float<double,高精度转低精度要强制类型转换(显式类型转换);超范围也要要强制转换
47 int a1=(int)45.23;
48 long a2=(long)456.5F;
49 int a3=(int)'d';
50 byte a4=(byte)132;
51 System.out.println(a1);
52 System.out.println(a2);
53 System.out.println(a3);
54 System.out.println(a4);//显示-124
55 }
56 }