How to access individual word from c++ vector? - c++

Question

At the end of the program I output the contents of a vector, the strings were inputted from a text file. The entire vector is outputted, but how do I just output one word? I am asking this because I will later need to modify each string.
#include<iostream>
#include<fstream>
#include<vector>
#include<algorithm>
using namespace std;
int main(){
ifstream in;
string line, file_name;
vector <string> phrase;
int total_words, total_letters, total_chars;
cout << "PIG LATIN PROGRAM" << endl;
cout << "Which file are you accessing? : ";
cin >> file_name;
in.open(file_name);
if (in.fail()) cout << "\nFile not found!" << endl;
while(getline(in, line)) phrase.push_back(line);
for(int i = 0; i < phrase.size(); i++){
int limit = phrase.size() - 1;
while(i < limit && phrase[i] == phrase[i]){
i++;
}
cout << phrase[i];
}

Answer 1

You could start by splitting the line in phrase[i] at points there's whitespace:
std::istringstream iss{phrase[i]};
std::vector<std::string> words;
std::string word;
while (iss >> word)
words.push_back(std::move(word));
std::istringstream creates an input stream - a bit like cin - that contains the full line of text read from your file and stored in phrase[i]. If you then use >> word it will extract one whitespace-delimited word of text at a time.
Say your line/phrase[i] input contained "the blue socks were her favourites", it'll be split nicely into words. If there is also punctuation in the line, some of the strings in words will embed that punctuation, e.g. "world.". If you care about that, you can learn to use std::string member functions to search in and edit the strings.
In the case of punctuation you could use
std::erase(std::remove_if(word.begin(), word.end(), std::ispunct), word.end()) to remove it (further details/explanation).

Answer 2

phrase[i] == phrase[i]
Well, that's just redundant. This will always return true for a vector holding strings.
for(int i = 0; (...); i++){
while( (...) ){
i++;
}
}
You are modifying variable i twice in this a single for loop. Once in the third parameter of for, and once in an inner while loop. It's almost never a good idea.
What's happening here is that you set i=0, then immediately set it to point to the last element of a vector (as the second condition in while is always true).
Then you print this element to console, which is the last line of your text file.
What you want to do, is:
1. Load text file line by line into a vector.
2. Each element of vector will hold a single line.
3. Split each line into a vector of WORDS (space separated).
4. Work with the resulting vector.
Or pheraps:
1. Load file word by word at the beginning.
vector<string> words;
copy( istream_iterator<string>{YourFileStream}, istream_iterator<string>{}, back_inserter{words} ); // this will copy the content of file directly into vector, white-space-separated (no need for while loop to do it)
for ( auto i = phrase.begin(); i != phrase.end(); ++i ) // it's the proper c++ way of iterating over a vector. very similar, but variable i will point to every element of vector in order ( not just to the index of an element )
{
// do some work on *i. at least:
std::cout << *i; // dereference operator (*) is needed here, since i doesn't hold index of an element, it's a "pointer" to an element
}
If you need the first approach ( to differentiate between words in different lines ), here you can find some excellent ways to separate a string by any delimeter (space, for example): The most elegant way to iterate the words of a string