挑出字符串中的数组、字母、空格个数

public interface CheckChar {
    public static void main(String[] args) {
        String str = "zhe ge xiao zi 1991 ni shi ge da huan dai";
        checkStr(str);
    }
    public static void checkStr(String str){

        char[] ch = str.toCharArray();
        int digital = 0;  int character = 0;
        int blank = 0;  int other = 0;
        for(char c:ch){
            if(c >='0' && c <='9')
                digital++;
            else if(c >='a' && c <='z'  || c >='A' && c <='Z')
                character++;
            else if(' '==c)
                blank++;
            else 
                other++;
        }
       System.out.println("数字个数: " + digital);
       System.out.println("英文字母个数: " + character);
       System.out.println("空格个数: " + blank);
       System.out.println("其他字符个数:" + other );
    }
}