Compare variable with each line from a txt file - c++

Question

I have to compare each line of a txt file with a user input variable.
If the userinput word exists within the txt file, it should prompt the user "The word exists." and if it does not, than exit the program.
This is what the text file looks like:
hello
hey
wow
your
Here is my code:
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
int main() {
ifstream file("words.txt");
string content;
string userinput;
while(file >> content) {
cout << content << endl; // gets all the lines from the txt file
while(userinput != "exit") {
// asks user for input
cin >> userinput;
// compares two inputs
if (userinput == content)
{
cout << "The word exists." << endl;
} else {
break;
}
if (userinput == "exit") {
break;
}
}
}
return 0;
}
Its not working for me. I am able to return all the words from the txt file but not able to compare the userinput text with the txt lines from the txt file. Any help would be great. Thanks!
Updated code:
while(iFile >> content) {
while(userinput != "exit") {
// asks user for input
cin >> userinput;
// compares two inputs
if (content.find(userinput) != std::string::npos)
{
cout << "The word exists." << endl;
} else {
break;
}
if (userinput == "exit") {
break;
}
}
}
P.S: I am pretty new to c++. A student

Answer 1

#include <string>
#include <iostream>
#include <fstream>
#include <unordered_set>
using namespace std;
int main()
{
fstream file("wy.txt");
string line;
unordered_set<string> res;
while(file>>line)
{
res.insert(line);
}
do
{
cout<<"Please input the word: "<<endl;
string str;
cin>>str;
if (res.find(str) != res.end())
cout << "The word exists." << endl;
else
break;
} while (true);
}
This code can work fine.

Answer 2

You are running a loop over each line-token in the file, in which you ask the user for guesses until he gives up for each? Nice one, but not what you said.
What you want to do instead:
Read the file, parsing it into word-tokens which you save in an std::unordered_set.
Then ask the user which word shall be matched.
Ask the std::unordered_map to divulge its secrets.
Try it.

Answer 3

When you are writing:
// compares two inputs
if (userinput == content)
You are indeed checking if the user has entered the exact text in content. What you want is checking if userinput is contained in content:
// check if the userinput is found in the text
if(content.find(userinput) != std::string::npos)
You need also to read the complete file. Right now you are reading from the input file each time you are asking an input from the user.
#include <iostream>
#include <fstream>
#include <memory>
#include <sstream>
#include <sys/types.h>
#include <sys/stat.h>
inline static bool fileExists(const std::string& name) {
struct stat buffer;
return (stat (name.c_str(), &buffer) == 0);
}
/// Read the file content and return as a string
static std::string readFile(const std::string &filename)
{
std::ifstream t(filename);
std::stringstream buffer;
buffer << t.rdbuf();
return buffer.str();
}
int main() {
std::string filename("words.txt");
if(!fileExists(filename))
// print error
return -1;
string content = readFile(filename);
string userinput;
... // handle userinput from now
Note that this is inefficient. Since you text is always the same and you are repeating searches, it could be preprocessed. There are multiple data structure that can help. For instance you could have a hash map and populate it with each line as keys.