reading from a textfile into an array

[sajenia]

i need to write a program in c++ that is going to read English sentences from a textfile, a line at a time and store them in an array. the file has 100 sentences each occupying a single line.

[arne]

i need to write a program in c++ that is going to read English sentences from a textfile, a line at a time and store them in an array. the file has 100 sentences each occupying a single line.

And what is it you have difficulties with?

[sajenia]

And what is it you have difficulties with?

having problems with array declaration. is it suppossed to be a one-dim array or a two-dim array?
i have managed to have the program read from a textfile but it is not storing into an array. displaying the senteces has to be from an array not from the textfile as it is doing.

[arne]

having problems with array declaration. is it suppossed to be a one-dim array or a two-dim array?
i have managed to have the program read from a textfile but it is not storing into an array. displaying the senteces has to be from an array not from the textfile as it is doing.

One dimensional: it could be an array of strings like this

vector<strings> sentences; 
 

[sajenia]

One dimensional: it could be an array of strings like this

vector<strings> sentences; 
 

i don't even understand this line of code that u've sent. can u elaborate. what is a vector anyway?

[arne]

i don't even understand this line of code that u've sent. can u elaborate. what is a vector anyway?

A vector is a container class from the C++ Standard Template library (STL). All you need to know for practical use, however, is that a vector can be used to store a sequence of values of a certain type, that it grows automatically if you need more space and that it grants efficient access. It's similar to a simple array, but somewhat more comfortable.

For example,

vector<string> vec_of_str;
vector<int> vec_of_int;
vector<double> vec_of_dbl;
 

define vectors that hold elements of type string, int and double, respectively.
BTW, string is also a type from the STL and no built-in type like int or float.
Please refer also to http://www.cppreference.com to get an idea what things you can do with vectors and strings.

Here comes the code that may do what you need. Have a look and try to understand it (I added some comments :))

#include <iostream>
#include <fstream>
#include <string>
#include <vector>
 
using namespace std;
 
int main( void ) 
{
    // define an infile stream
    ifstream fin( "textfile.txt" );
 
    // define a vector of strings
    vector<string> sentences;
 
    //define a temporary string
    string tmp_str;
 
    // read the file line by line into tmp_str
    while( getline( fin, tmp_str ) ) {
 
        // append the tmp_str as a new last 
                // element to sentences 
        sentences.push_back( tmp_str );
    }
 
    // print out the 3rd element of our vector
    cout << sentences[2];
 
    return 0;
}