编写一个程序，输入一个字符串，统计其中与多少个单词？单词之间用空格分开

Question

我是初学者，能不能说清楚点，谢谢啦！

Answer 1

import java.util.Scanner;

public class Test {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("请输入:");
String sentence = input.nextLine();
// 将输入的句子转化为单词数组
String[] words = sentence.split(" ");
// 单词数组的长度就是单词数
System.out.println("共有 " + words.length + " 个单词.");
}
}

Answer 2

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;
public class Test {

public static void main(String[] args){

Scanner s = new Scanner(System.in);
System.out.println("please enter ...");
String str = s.nextLine();
String[] arr = str.split(" ");
Map<String,Integer> result = new HashMap<String,Integer>();

for(int i=0;i<arr.length;i++){
Set<String> keys = result.keySet();
if(keys.contains(arr[i])){
result.put(arr[i], result.get(arr[i])+1);
}else{
result.put(arr[i], 1);
}
}

Set<String> keys = result.keySet();
for(String key:keys){
System.out.println(key+"出现:"+result.get(key)+"次");
}
}
}