🔒 Locked

How do iterators work

Started by Sagar_Indurkhya Jul 11, 2004 at 4:05 PM 2 replies 300+ views

Original Post

Jul 11, 2004 at 4:05 PM

I have this code: Assumptions - 1) data is a vector filled with strings from a file. 2) the first string is an int.



//convert string to int 
int x;
stringstream StrToInt(data[0]);
StrToInt >> x;

cout << x << "\n";

x turns out to be some number like -834039483, when it should be 5. why isn't this working. Do I need to use an iterator?

smart_idiot

183

smart_idiot

Jul 11, 2004 at 4:43 PM

An iterator is like a position in something; and they're used almost the same way as a pointer.

Example:

#include <iostream>#include <string>using namespace std;int main() {  string word("Hello.");   for(string::iterator character = word.begin(); character != word.end(); ++character)   cout << *character << endl;    return 0; }

That goes through each character in the string and prints it.

As for what you're doing; it has nothing to do with iterators. It kind of looks like data[0] is empty and nothing was assigned to x, leaving it filled with garbage. Try printing the value of data[0] to make sure it actually contains what you think it does.

Sagar_Indurkhya

Author

Sagar_Indurkhya

Jul 11, 2004 at 5:48 PM

The first line of the data is suppose to be a 5.
However, when I print the entire contents of my vector, it prints everything after the first line.

Chris Hare

Jul 11, 2004 at 6:21 PM

int main(){	const char* c = "5";	stringstream StrToInt;	StrToInt << c;	int x = 0;	StrToInt >> x;	cout << x << "\n";	return 0;}

???

Topic Locked

This topic has been locked by a moderator. New replies are not allowed.