题解 | #统计字符串中字母出现次数# str.replac

import java.util.Scanner;
 
public class Main {
    public static void main(String[] args) {
        String string = "H e l l o ! n o w c o d e r";
        Scanner scanner= new Scanner(System.in);
        String word = scanner.next();
        scanner.close();
        System.out.println(check(string, word));
    }
    public static int check(String str,String word){
        return str.length() - str.replace(word,"").length();
    }
}

// import java.util.Scanner;

// public class Main {
//     public static void main(String[] args) {
//         String string = "H e l l o ! n o w c o d e r";
//         Scanner scanner= new Scanner(System.in);
//         String word = scanner.next();
//         scanner.close();
//         System.out.println(check(string, word));
//     }

//     public static int check(String str, String word) {

//         //write your code here......
//         int n =0;
//         int i = 0;

//         while(i < str.length())
//         {
//             if(str.indexOf(word, i) != -1)
//             {
//                 n++;
//                 i = str.indexOf(word,i)+1;
//             }
//             else
//             {
//                 break;
//             }
//         } 

//         return n;
        

//     }
// }

str.replace()你学会了么

替换之后求长度变化