我是编程新手。我一直在尝试用C ++编写一个函数,它将字符串的内容分解为给定参数的字符串数组,例如:
string str = "___this_ is__ th_e str__ing we__ will use__";
应返回字符串数组:
cout << stringArray[0]; // 'this'
cout << stringArray[1]; // ' is'
cout << stringArray[2]; // ' th'
cout << stringArray[3]; // 'e str'
cout << stringArray[4]; // 'ing we'
cout << stringArray[5]; // ' will use'
我可以很好地对字符串进行标记,但对我来说最难的部分是如何在为当前字符串toke分配字符串之前指定stringArray中的元素数量,以及如何从函数中返回stringArray。
有人会告诉我如何编写这个函数吗?
Edit1:我不一定需要将结果放在字符串数组中的任何容器中,我可以将其作为带有某种索引的常规变量调用。
答案 0 :(得分:11)
这是我第一次尝试使用向量和字符串:
vector<string> explode(const string& str, const char& ch) {
string next;
vector<string> result;
// For each character in the string
for (string::const_iterator it = str.begin(); it != str.end(); it++) {
// If we've hit the terminal character
if (*it == ch) {
// If we have some characters accumulated
if (!next.empty()) {
// Add them to the result vector
result.push_back(next);
next.clear();
}
} else {
// Accumulate the next character into the sequence
next += *it;
}
}
if (!next.empty())
result.push_back(next);
return result;
}
希望这能让你对如何解决这个问题有所了解。在您的示例字符串上,它使用以下测试代码返回正确的结果:
int main (int, char const **) {
std::string blah = "___this_ is__ th_e str__ing we__ will use__";
std::vector<std::string> result = explode(blah, '_');
for (size_t i = 0; i < result.size(); i++) {
cout << "\"" << result[i] << "\"" << endl;
}
return 0;
}
答案 1 :(得分:9)
使用STL(抱歉没有编译器未经测试)
#include <vector>
#include <string>
#include <sstream>
int main()
{
std::vector<std::string> result;
std::string str = "___this_ is__ th_e str__ing we__ will use__";
std::stringstream data(str);
std::string line;
while(std::getline(data,line,'_'))
{
result.push_back(line); // Note: You may get a couple of blank lines
// When multiple underscores are beside each other.
}
}
//或定义一个标记
#include <vector>
#include <string>
#include <iterator>
#include <algorithm>
#include <sstream>
struct Token: public std::string // Yes I know this is nasty.
{ // But it is just to demosntrate the principle.
};
std::istream& operator>>(std::istream& s,Token& t)
{
std::getline(s,t,'_');
// ***
// Remove extra '_' characters from the stream.
char c;
while(s && ((c = s.get()) != '_')) {/*Do Nothing*/}
if (s)
{
s.unget(); // Put back the last char as it is not '_'
}
return s;
}
int main()
{
std::vector<std::string> result;
std::string str = "___this_ is__ th_e str__ing we__ will use__";
std::stringstream data(str);
std::copy(std::istream_iterator<Token>(data),
std::istream_iterator<Token>()
std::back_inserter(result)
);
}
答案 2 :(得分:3)
它对我有用:
#include <iostream>
#include <vector>
#include <string>
using namespace std;
vector<string> explode( const string &delimiter, const string &explodeme);
int main(int argc, char *argv[])
{
string str = "I have a lovely bunch of cocoa nuts";
cout<<str<<endl;
vector<string> v = explode(" ", str);
for(int i=0; i<v.size(); i++)
cout <<i << " ["<< v[i] <<"] " <<endl;
}
vector<string> explode( const string &delimiter, const string &str)
{
vector<string> arr;
int strleng = str.length();
int delleng = delimiter.length();
if (delleng==0)
return arr;//no change
int i=0;
int k=0;
while( i<strleng )
{
int j=0;
while (i+j<strleng && j<delleng && str[i+j]==delimiter[j])
j++;
if (j==delleng)//found delimiter
{
arr.push_back( str.substr(k, i-k) );
i+=delleng;
k=i;
}
else
{
i++;
}
}
arr.push_back( str.substr(k, i-k) );
return arr;
}
答案 3 :(得分:1)
如果你坚持让stringArray
数组与std::vector<>
相反(这是正确的做法),你必须要么:
使用向量更容易vector::push_back()
将新内容添加到最后。所以:
vector* explode(string s){
vector<string> *v = new vector<string>
//...
// in a loop
v->push_back(string_fragment);
//...
return v;
}
毕竟不需要为了完整性而留下来。
要返回使用char **
的字符串数组。
在
中char ** explode(const char *in){
...
}
BTW--调用函数如何知道返回数组中有多少元素?你也必须解决这个问题。使用std::vector<>
除非受到外力的限制......
答案 4 :(得分:1)
您可以使用字符串(std::vector<std::string>
)的向量,使用push_back将每个标记附加到它,然后从tokenize函数返回它。
答案 5 :(得分:1)
使用std :: vector作为动态数组并将其作为结果返回。
答案 6 :(得分:1)
也许您应该使用列表而不是数组。这样你就不需要提前了解元素的数量。您也可以考虑使用STL容器。
答案 7 :(得分:0)
等到您的数据结构类,然后使用链表对其进行编码。如果它是用于家庭作业,你可能只需启动阵列就可以逃脱。
答案 8 :(得分:0)
以下代码:
template <typename OutputIterator>
int explode(const string &s, const char c, OutputIterator output) {
stringstream data(s);
string line;
int i=0;
while(std::getline(data,line,c)) { *output++ = line; i++; }
return i;
}
int main(...) {
string test="H:AMBV4:2:182.45:182.45:182.45:182.45:182.41:32:17700:3229365:201008121711:0";
cout << test << endl;
vector<string> event;
**This is the main call**
int evts = explode(test,':', back_inserter(event));
for (int k=0; k<evts; k++)
cout << event[k] << "~";
cout << endl;
}
<强>输出强>
H:AMBV4:2:182.45:182.45:182.45:182.45:182.41:32:17700:3229365:201008121711:0
H~AMBV4~2~182.45~182.45~182.45~182.45~182.41~32~17700~3229365~201008121711~0~
答案 9 :(得分:0)
这是我的熟化代码(完整)。对于有相同需求的人来说,这可能是有用的。
#include <string>
#include <iostream>
#include <sstream>
#include <vector>
using namespace std;
int main(){
std::string s = "scott:tiger:mushroom";
std::string delimiter = ":";
std::vector<std::string> outputArr;
size_t pos = 0;
std::string token;
while ((pos = s.find(delimiter)) != std::string::npos) {
token = s.substr(0, pos);
s.erase(0, pos + delimiter.length());
outputArr.push_back(token);
}
outputArr.push_back(s);
// Printing Array to see the results
std::cout<<"====================================================================================\n";
for ( int i=0;i<outputArr.size();i++){
std::cout<<outputArr[i]<<"\n";
}
std::cout<<"====================================================================================\n";
}
干杯!!
答案 10 :(得分:0)
我认为我写了一个更简单的解决方案。
std::vector<std::string> explode(const std::string& string, const char delimiter) {
std::vector<std::string> result;
unsigned int start = 0, pos = 0;
while (pos != string.length()) {
if (string.at(pos) == delimiter || pos + 1 == string.length()) {
unsigned int size = (pos - start) + ((pos + 1) == string.length() ? 1 : 0);
if (size != 0) { // Make this 'if' as a option? like a parameter with removeEmptyString?
result.push_back(string.substr(start, size));
}
start = pos + 1;
}
pos++;
}
return std::move(result);
}
答案 11 :(得分:0)
这对我有用:
#include <iostream>
#include <vector>
#include <string>
#include <sstream>
using namespace std;
vector<string> split(string str, char delimiter) {
vector<string> internal;
stringstream ss(str); // Turn the string into a stream.
string tok;
while(getline(ss, tok, delimiter)) {
internal.push_back(tok);
}
return internal;
}
int main(int argc, char **argv) {
string myCSV = "one,two,three,four";
vector<string> sep = split(myCSV, ',');
// If using C++11 (which I recommend)
/* for(string t : sep)
* cout << t << endl;
*/
for(int i = 0; i < sep.size(); ++i)
cout << sep[i] << endl;
}
来源:http://code.runnable.com/VHb0hWMZp-ws1gAr/splitting-a-string-into-a-vector-for-c%2B%2B
答案 12 :(得分:0)
# turn a string into a deque based on a delimiter string
bool tolist(deque<string>& list,string basis,const string& cutter) {
bool found = false;
if (!cutter.empty()) {
while (!basis.empty() ) {
string::size_type pos = basis.find(cutter);
if (pos != string::npos) {
found = true;
list.push_back(basis.substr(0, pos)); //pos says 2
basis = basis.substr(pos+cutter.size(),string::npos);
} else {
list.push_back(basis);
basis.clear();
}
}
}
return found;
}