基本运算符

 1 package operation;
 2 
 3 public class Demo1 {
 4     public static void main(String[] args) {
 5         //二元运算符
 6         //Ctrl+D :复制当前行到下一行
 7         int a=10;
 8         int b=20;
 9         int c=30;
10         int d=40;
11 
12         System.out.println(a+b);
13         System.out.println(a-b);
14         System.out.println(a*b);
15         System.out.println(a/(double)b);
16     }
17 }
18 ===============================================================
19 package operation;
20 
21 public class Demo2 {
22     public static void main(String[] args) {
23 
24 //       运算结果按照类型的优先级
25 //      类型转换：byte、short、char用运算符运算后自动转型为int类型
26         long a =123123123123L;
27         int b =123;
28         short c =10;
29         byte d =8;
30 
31         System.out.println(a+b+c+d);//long
32         System.out.println(b+c+d);//int
33         System.out.println(c+d);//int
34 
35         //关系运算符f返回的结果：正确，错误  布尔值
36 
37         int a2 = 10;
38         int b2 = 20;
39         int c2 = 22;
40         //取余，模运算
41         System.out.println(c2%a2);
42 
43         System.out.println(a2>b2);
44         System.out.println(a2<b2);
45         System.out.println(a2==b2);
46         System.out.println(a2!=b2);
47 
48 
49     }
50 }