operate_str = initial_str.substr(0, 3);

?? ?//使用substr函數(shù)實現(xiàn)已知序號的字符串切片
?? ?string initial_str = "0123456789";
?? ?string operate_str;
?? ?operate_str = initial_str.substr(0, 3); //從0號開始,切片長度為3，即截取0到（0 + 3 - 1）號
?? ?cout << "operate_str = " << operate_str << endl; //輸出結(jié)果為012

int start = initial_str.find(key1);?

?? ?//使用substr函數(shù)配合find函數(shù)實現(xiàn)已知特征串的字符串切片
?? ?string key1 = "23"; //定義特征串
?? ?int len = 5; //定義切片長度
?? ?int start = initial_str.find(key1); //返回特征串第一個字符的序號，此處為2
?? ?string key2 = "abc"; //測試不存在特征串返回值
?? ?int result = initial_str.find(key2);
?? ?cout << "result = " << result << endl; //對象中不存在特征串，此處輸出為 -1
?? ?operate_str = initial_str.substr(start, len); //從start開始，切片長度為len，即截取start到（start + len - 1）號
?? ?cout << "operate_str = " << operate_str << endl; //輸出結(jié)果為23456

void SplitString(std::string str){
	if(str.empty()){
		return;
	}
	vector<std::string> res;
	const char split = '\n'; //分割符
	std::string strs = str + split;
	size_t i = 0;
	size_t pos = strs.find(split,i);
	while(pos ! = strs.npos){
		string temp = strs.substr(i, pos - i);
		res.push_back(temp);
		i = pos + 1;
		pos = strs.find(split,i) 
	}
	for(int i=0;i<res.size();i++){
		cout>>res.[i]>>endl;
	}
}