java 学习day2 

 1 package com.Diyi.day01;
 2 
 3 public class LiShauiday03_算术运算符 {
 4     public static void main(String[] args) {
 5         int a = 99;
 6         int b = 100;
 7         double d = 9;
 8         int c = (int)9.0;// 强制转换,强制高到低.  double>>>int
 9                          //数值和数据  不能和布尔 相互转
10         System.out.println('q'+'q');
11         //System.out.println(true+true);
12         System.out.println(99+1);
13         System.out.println('s'+1);
14         System.out.println("aaaa"+44+55);
15         System.out.println(44+55+"aaaa");
16         System.out.println("Li"+"Shuai"+'l');
17         System.out.println('a'+"lishuai");
18         System.out.println('a'+'l');
19         System.out.println('a'+1);
20         System.out.println("shsh"+true);
21         System.out.println();
22     }
23 }
 1 package com.Diyi.day01;
 2 /*
 3  *  基本数据类型     整数  浮点  字符  布尔  字节
 4  */
 5 public class LiShuai01 {
 6     public static void main(String[] args) {
 7         int a = 123;
 8         char i = 'b';
 9         int c = 'c';
10     System.out.println("lishaui666"); //类类型(为引用类型)    String
11         System.out.println('q');
12         System.out.println('a'+666);
13         System.out.println(c);
14         System.out.println(i);
15         System.out.println(a);
16         String ww = "lishaui";
17         boolean s = false;//布尔类型
18         System.out.println(ww);
19         System.out.println(s);
20         {
21             String shuai = "lishaui2";
22         System.out.println(a+c);
23         }
24         //System.out.println(shuai);
25             // int 6shuai = 66;   false
26     }
27
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 1 package com.Diyi.day01;
 2 
 3 public class LiShuai02 {
 4         public static void main(String[] args) {
 5 //            数据类型 变量名 = 数据;
 6             int j,k,l;
 7             String v = "ss";
 8             j = 10;
 9             k = 90; 
10             l = 30;
11             int i = 100;
12             String c = "shuai";
13 //            boolean c =ture; 
14             System.out.println(c+k+l);
15             System.out.println(k+l+c);
16             System.out.println(k+l);
17             System.out.println(j*20);
18             int a = 19;
19             int b = a+90;
20             System.out.println(b);
21              a = 99;
22              i = 22;
23              System.out.println(a);
24              System.out.println(i);
25     }
26 
27 }
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posted @ 2021-04-11 21:29  李帅1218  阅读(35)  评论(1)    收藏  举报