0基础学java_String类及常用方法

String类是编程中经常使用的字符串类

String类的两种实例化方法

直接赋值

1 package com.feimao.code;
2 
3 public class StringDemo1 {
4     public static void main(String args[]){
5         String name = "肥猫";
6         System.out.println("姓名：" + name);
7     }
8 }

2.通过关键字new

 1 package com.feimao.code;
 2 
 3 
 4 
 5 public class StringDemo2 {
 6 
 7     public static void main(String args[]){
 8 
 9         String name = new String("肥猫");//实例化String对象
10 
11         System.out.println("姓名：" + name);
12 
13     }
14 
15 }

String的两种比较方法

一种是用“==”，比较的是地址值

 1  package com.feimao.code;
 2 
 3 
 4 
 5 public class StringDemo02 {
 6 
 7     public static void main(String args[]){
 8 
 9         String str1 = "肥猫";
10 
11         String str2 = new String("肥猫");
12 
13         String str3 = str2;
14 
15         System.out.println("str1 == str2 -->  " + (str1 == str2));
16 
17         System.out.println("str1 == str3 -->  " + (str1 == str3));
18 
19         System.out.println("str2 == str3 -->  " + (str2 == str3));
20 
21     }
22 
23 
24 
25 }

2.另外一种是使用equals方法

 1 package com.feimao.code;
 2 
 3 
 4 
 5 public class StringDemo02 {
 6 
 7     public static void main(String args[]){
 8 
 9         String str1 = "肥猫";
10 
11         String str2 = new String("肥猫");
12 
13         String str3 = str2;
14 
15         System.out.println("str1 equals str2 -->  " + (str1.equals(str2)));
16 
17         System.out.println("str1 equals str3 -->  " + (str1.equals(str3)));
18 
19         System.out.println("str2 equals str3 -->  " + (str2.equals(str3)));
20 
21     }
22 
23 
24 
25 }

0基础学java_String类及常用方法

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