string *parse(string str,int from){
int i=0,n=0,j,k;
i=j=from;
string *data=new string[6];
while(str[i]){
if(str[i]==' '){
for(k=0;k<(i-j-1);k++){
data[n][k]=str[j+k]; << Error takes place here
}
data[n][k]='\0';
j=i;
n++;
}
i++;
}
return data;
}
Thanks for your help. I tried to debug but without success, what am I missing?
The problem is that elements data[i] of the data array all have the length of zero. That is why the assignment data[n][k] is always outside of data[n]'s range.
One way of fixing this would be using concatenation:
data[n] += str[j+k];
A better approach would be eliminating the loop altogether, and using substr member function of std::string instead: it lets you cut out a portion of str knowing the desired length and the starting position.
In addition, you are returning a pointer to a local array, which is undefined behavior. You should replace an array with a vector<string>, and add items to it using push_back.
Finally, you need to push the final word when the str does not end in a space.
Here is your modified program that uses the above suggestions:
vector<string> parse(string str,int from){
int i=from, j=from;
vector<string> data;
while(str[i]){
if(str[i]==' '){
data.push_back(str.substr(j, i-j+1));
j=i+1;
}
i++;
}
if (j != str.size()) {
data.push_back(str.substr(j));
}
return data;
}
Here is a demo on ideone.
data starts with 0 length, data[n][k] out of boundry. data[n][k]='\0' is not correct way of using C++ string and string * is considered of bad practice.
To separate a string by space, try:
#include <string>
#include <vector>
#include <sstream>
std::string data("hi hi hi hi hi");
std::stringstream ss(data);
std::string word;
std::vector<std::string> v;
while(std::getline(ss, word, ' '))
{
v.push_back(word);
}
datastarts with 0 length,data[n][k]out of boundry