Character类

java.lang.Character
父类:java.lang.Object
1.Character构造方法
public Character(char value)
eg: Character c = new Character('a')
2.Character类部分方法
　　1>public static boolean isDigit(char ch)

　　1>public static boolean isUpperCase(char ch)

　　1>public static boolean isLowerCase(char ch)

　　1>public static char toUpperCase(char ch)　　

　　1>public static char toLowerCase(char ch)

public class CharacterDemo {
    public static void main(String[] args) {
        Character leo9257 =new Character('@');
        char guiyang = leo9257.charValue();
        Character.isDigit('0');
        Character.isUpperCase('A');
        Character.isLowerCase('a');
        
        //判断一下一个字符串中各种字符的个数:
        //String s = "nanjing.guiyang@2009";
        /*int u_count=0;
        int l_count=0;
        int d_count=0;
        int o_count=0;
        
        //第一种方式:charAt();
        for (int i = 0; i < s.length(); i++) {
            char ch = s.charAt(i);
            if(Character.isUpperCase(ch)){
                u_count++;            
            }else if(Character.isLowerCase(ch)){
                l_count++;                
            }else if(Character.isDigit(ch)){
                d_count++;
            }else{
                o_count++;
            }            
        }        */
    //第二种方式:toCharArray();
            String s = "nanjing.guiyang@2009";
            int u_count=0;
            int l_count=0;
            int d_count=0;
            int o_count=0;
            char[] chs= s.toCharArray();
            for (int i = 0; i < chs.length; i++) {
                if(Character.isUpperCase(chs[i])){
                    u_count++;            
                }else if(Character.isLowerCase(chs[i])){
                    l_count++;                
                }else if(Character.isDigit(chs[i])){
                    d_count++;
                }else{
                    o_count++;
                }    
            }    
    }
}