如何迭代由空格分隔的单词组成的字符串中的单词？
注意，我对C字符串函数或那种字符操作/访问不感兴趣。比起效率，我更喜欢优雅。我当前的解决方案：
#include <iostream>
#include <sstream>
#include <string>
using namespace std;
int main() {
string s = "Somewhere down the road";
istringstream iss(s);
do {
string subs;
iss >> subs;
cout << "Substring: " << subs << endl;
} while (iss);
}
当前回答
我无法相信这些答案有多复杂。为什么没有人提出这么简单的建议？
#include <iostream>
#include <sstream>
std::string input = "This is a sentence to read";
std::istringstream ss(input);
std::string token;
while(std::getline(ss, token, ' ')) {
std::cout << token << endl;
}
其他回答
对于那个些需要使用字符串分隔符拆分字符串的人，也许可以尝试我的以下解决方案。
std::vector<size_t> str_pos(const std::string &search, const std::string &target)
{
std::vector<size_t> founds;
if(!search.empty())
{
size_t start_pos = 0;
while (true)
{
size_t found_pos = target.find(search, start_pos);
if(found_pos != std::string::npos)
{
size_t found = found_pos;
founds.push_back(found);
start_pos = (found_pos + 1);
}
else
{
break;
}
}
}
return founds;
}
std::string str_sub_index(size_t begin_index, size_t end_index, const std::string &target)
{
std::string sub;
size_t size = target.length();
const char* copy = target.c_str();
for(size_t i = begin_index; i <= end_index; i++)
{
if(i >= size)
{
break;
}
else
{
char c = copy[i];
sub += c;
}
}
return sub;
}
std::vector<std::string> str_split(const std::string &delimiter, const std::string &target)
{
std::vector<std::string> splits;
if(!delimiter.empty())
{
std::vector<size_t> founds = str_pos(delimiter, target);
size_t founds_size = founds.size();
if(founds_size > 0)
{
size_t search_len = delimiter.length();
size_t begin_index = 0;
for(int i = 0; i <= founds_size; i++)
{
std::string sub;
if(i != founds_size)
{
size_t pos = founds.at(i);
sub = str_sub_index(begin_index, pos - 1, target);
begin_index = (pos + search_len);
}
else
{
sub = str_sub_index(begin_index, (target.length() - 1), target);
}
splits.push_back(sub);
}
}
}
return splits;
}
这些片段由3个函数组成。坏消息是使用str_split函数，您将需要另外两个函数。是的，这是一大块代码。但好消息是，这两个附加功能可以独立工作，有时也很有用
测试main（）块中的函数如下：
int main()
{
std::string s = "Hello, world! We need to make the world a better place. Because your world is also my world, and our children's world.";
std::vector<std::string> split = str_split("world", s);
for(int i = 0; i < split.size(); i++)
{
std::cout << split[i] << std::endl;
}
}
它将产生：
Hello,
! We need to make the
a better place. Because your
is also my
, and our children's
.
我认为这不是最有效的代码，但至少它可以工作。希望有帮助。
这是我的方法，切割和分割：
string cut (string& str, const string& del)
{
string f = str;
if (in.find_first_of(del) != string::npos)
{
f = str.substr(0,str.find_first_of(del));
str = str.substr(str.find_first_of(del)+del.length());
}
return f;
}
vector<string> split (const string& in, const string& del=" ")
{
vector<string> out();
string t = in;
while (t.length() > del.length())
out.push_back(cut(t,del));
return out;
}
顺便说一下，如果我能做些什么来优化这个。。
// adapted from a "regular" csv parse
std::string stringIn = "my csv is 10233478 NOTseparated by commas";
std::vector<std::string> commaSeparated(1);
int commaCounter = 0;
for (int i=0; i<stringIn.size(); i++) {
if (stringIn[i] == " ") {
commaSeparated.push_back("");
commaCounter++;
} else {
commaSeparated.at(commaCounter) += stringIn[i];
}
}
最后你会得到一个字符串向量，句子中的每个元素都用空格隔开。唯一的非标准资源是std:：vector（但由于涉及std:：string，我认为它是可以接受的）。
空字符串保存为单独的项。
对于一个大得离谱而且可能是冗余的版本，可以尝试很多For循环。
string stringlist[10];
int count = 0;
for (int i = 0; i < sequence.length(); i++)
{
if (sequence[i] == ' ')
{
stringlist[count] = sequence.substr(0, i);
sequence.erase(0, i+1);
i = 0;
count++;
}
else if (i == sequence.length()-1) // Last word
{
stringlist[count] = sequence.substr(0, i+1);
}
}
它并不漂亮，但总的来说（除了标点符号和一系列其他错误）它是有效的！
#include <vector>
#include <string>
#include <sstream>
int main()
{
std::string str("Split me by whitespaces");
std::string buf; // Have a buffer string
std::stringstream ss(str); // Insert the string into a stream
std::vector<std::string> tokens; // Create vector to hold our words
while (ss >> buf)
tokens.push_back(buf);
return 0;
}
