题解 | #计算某字母出现次数#

字符串转字符数组

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String s1 = in.nextLine();
        String s2 = in.nextLine();
        char[] ss1 = s1.trim().toLowerCase().toCharArray();
        char ss2 = s2.trim().charAt(0);
        int num = 0;
        for (int i = 0; i <ss1.length ; i++) {
            if(ss2==ss1[i] || (ss2+32)==ss1[i]){
                    num++;
            }
        }
        System.out.println(num);
    }
}