解题思路

public class Test2{
    public static void main(String[] args){
        Scanner scanner = new Scanner(System.in); //创建对象
        String str = scanner.nextLine().toLowerCase();
        Character c =  scanner.nextLine().toLowerCase().charAt(0);
        Character.toLowerCase(c);

        int count = 0;
        for(int i = 0; i < str.length(); i++){
            if(c == str.charAt(i)){
                count++;
            }
        }
        System.out.println(count);
    }
}