Java统计字符串中大小写字母，数字个数

//统计大写字符，小写字符，数字字符

public class testString {

public static void main(String[] args){

Scanner sc = new Scanner(System.in);

System.out.println("请输入一个字符串：");

String str = sc.next();

int big_count = 0;

int small_count = 0;

int number_count = 0;

for (int i = 0; i < str.length(); i++) {

char c = str.charAt(i);

if(c >= 'a' && c <= 'z'){

small_count ++;

}

if(c >= 'A' && c <='Z'){

big_count ++;

}

if(c >= '0' && c <= '9'){

number_count ++;

}

}

System.out.println("大写字符数量为：" + big_count);

System.out.println("小写字符数量为：" + small_count);

System.out.println("数字字符数量为：" + number_count);

}

}

运行结果：