【C++基础】stringstream

stringstream 将字符串对象与流相关联，允许从字符串中读取，有点类似cin
方法：

1. 运算符 << ：将字符串添加到 stringstream 对象；
2. 运算符 >> ：从 stringstream 对象中读取内容；
3. stringstream（const string& str）：用 str 构造一个 stringstream 对象，

应用场景：

1. 计算字符串中的单词个数：
   输入：“hello world c plus plus”
   输出：5

#include <iostream>
#include <sstream>
#include <string>

using namespace std;

int main() {
	string str = "hello world c plus plus";
	int count = 0;
	stringstream ss(str);
	string word;
	while (ss >> word)
		count++;
	cout << count << endl;

	system("pause");
	return 0;
}

2.打印字符串中单个单词出现的频率
输入：“hello word c plus plus learning c plus plus”
输出：hello-1
world-1
c-2
plus-4
learning-1

#include <iostream>
#include <sstream>
#include <string>
#include <map>
using namespace std;

int main() {
	string str = "hello word c plus plus learning c plus plus";
	int count = 0;
	map<string, int> freq;
	stringstream ss(str);
	string word;
	while (ss >> word)
		freq[word]++;
	
	for (auto it = freq.begin(); it != freq.end(); ++it) {
		cout << it->first << "->" << it->second << endl;
	}

	system("pause");
	return 0;
}

标签：word,string,基础,C++,plus,str,stringstream,include
来源： https://blog.csdn.net/m0_47902113/article/details/121877876