基本数据类型和String相互转换

Posted 2020-10-25 celineluo

 1 package com.jdk7.chapter5;
 2 
 3 public class BasicToString {
 4     /**
 5      * 基本数据类型转换为String
 6      * 方法一：String.valueOf(基本数据类型)
 7      * 方法二：基本数据类型的封装类.valueOf(基本数据类型)
 8      * 方法三：直接在输出流中打印
 9      */
10     public static void intToStr(int n){
11         System.out.println("String.valueOf("+n+")>"+String.valueOf(n));
12         System.out.println("Integer.valueOf("+n+").toString()>"+Integer.valueOf(n).toString());
13         System.out.println("空格+"+n+">"+n);
14     }
15     
16     /**
17      * String转换为基本数据类型的封装类
18      * 方法一：基本数据类型的封装类.parseXxx(String)
19      * 方法二：new 基本数据类型的封装类(String)
20      * @param str
21      */
22     public static void strToInt(String str){
23         System.out.println("Integer.parseInt("+str+")>"+Integer.parseInt(str));
24         System.out.println("(new Integer("+str+")).toString()>"+(new Integer(str)).toString());
25     }
26     
27     public static void doubleToStr(double dou){
28         System.out.println("String.valueOf("+dou+")>"+String.valueOf(dou));
29         System.out.println("Double.valueOf("+dou+").toString()>"+Double.valueOf(dou).toString());
30         System.out.println("空格+"+dou+">"+dou);
31     }
32     
33     public static void strToDouble(String src){
34         System.out.println("Double.parseDouble("+src+")>"+Double.parseDouble(src));
35         System.out.println("new Double("+src+")>"+new Double(src));
36     }
37     public static void main(String[] args) {
38         BasicToString.intToStr(10);
39         BasicToString.strToInt("35536");
40         BasicToString.doubleToStr(4234.354);
41         BasicToString.strToDouble("7994.46378");
42     }
43 }
44 
45 
46 执行结果：
47 String.valueOf(10)>10
48 Integer.valueOf(10).toString()>10
49 空格+10>10
50 Integer.parseInt(35536)>35536
51 (new Integer(35536)).toString()>35536
52 String.valueOf(4234.354)>4234.354
53 Double.valueOf(4234.354).toString()>4234.354
54 空格+4234.354>4234.354
55 Double.parseDouble(7994.46378)>7994.46378
56 new Double(7994.46378)>7994.46378