Java中Character类的概述及其详解

迷南。 2022-02-09 10:57 294阅读 0赞

**Character类概述：**  
Character类在对象中包装一个基本类型char的值，此外，该类提供了几种方法，以确定字符的类别(小写字母，数字，等等)，并将字符从大写转换成小写。反之则亦然。  
**构造方法：**  
Character(char value)  
示例代码如下：

public class CharacterDemo {
    	public static void main(String[] args) {
    		//创建对象
    		//Charcter ch = new Character((char) 97);
    		Character ch = new Character('a');
    		System.out.println("ch:"+ch);
    	}
    }

运行结果：  
ch:a

--------------------

**几个主要方法：**

*  public static boolean isUpperCase(char ch):判断给定的字符是否是大写字符
 *  public static boolean isLowerCase(char ch):判断给定的字符是否是小写字符
 *  public static boolean isDigit(char ch):判断给定的字符是否是数字字符
 *  public static char toUpperCase(char ch):把给定的字符转换为大写字符
 *  public static char toLowerCase(char ch):把给定的字符转换为小写字符

代码示例：

public class CharacterDemo {
    	public static void main(String[] args) {
    		//public static boolean isUpperCase(char ch):判断给定的字符是否是大写字符
    		System.out.println("isUpperCase:"+Character.isUpperCase('A'));
    		System.out.println("isUpperCase:"+Character.isUpperCase('a'));
    		System.out.println("isUpperCase:"+Character.isUpperCase('0'));
    		System.out.println("---------------------------------");
    		
    		//public static boolean isLowerCase(char ch):判断给定的字符是否是小写字符
    		System.out.println("isLowerCase:"+Character.isLowerCase('A'));
    		System.out.println("isLowerCase:"+Character.isLowerCase('a'));
    		System.out.println("isLowerCase:"+Character.isLowerCase('0'));
    		System.out.println("---------------------------------");
    		
    		//public static boolean isDigit(char ch):判断给定的字符是否是数字字符
    		System.out.println("isDigit:"+Character.isDigit('A'));
    		System.out.println("isDigit:"+Character.isDigit('a'));
    		System.out.println("isDigit:"+Character.isDigit('0'));
    		System.out.println("---------------------------------");
    		
    		//public static char toUpperCase(char ch):把给定的字符转换为大写字符
    		System.out.println("toUpperCase:"+Character.toUpperCase('A'));
    		System.out.println("toUpperCase:"+Character.toUpperCase('a'));
    		System.out.println("---------------------------------");
    		
    		//public static char toLowerCase(char ch):把给定的字符转换为小写字符
    		System.out.println("toLowerCase:"+Character.toLowerCase('A'));
    		System.out.println("toLowerCase:"+Character.toLowerCase('a'));
    		
    	}
    }

运行结果：

isUpperCase:true  
isUpperCase:false  
isUpperCase:false

--------------------

isLowerCase:false  
isLowerCase:true  
isLowerCase:false

--------------------

isDigit:false  
isDigit:false  
isDigit:true

--------------------

toUpperCase:A  
toUpperCase:A

--------------------

toLowerCase:a  
toLowerCase:a