C++ Function to Search for A Numeric Value in a File - c++

Question

I have an assignment where I must create a function that takes a filename as a parameter, opens the file, asks a user to enter a value to be searched for, and then searches the file for that value. The file I was given to use for this assignment is a file with a list of revenue and expense values. I have tried just about everything and keep receiving the "value not found" prompt even when I enter a value that i know is in the file.
The code is
void numberSearch(string fileName)
{
string searchVal;
cout << "\nWhat value would you like to search for?\n";
cin.ignore();
getline(cin, searchVal);
ifstream file; //create input file object that will be read from
file.open(fileName); //"ifstream file (fileName)"
if (!file)
{
cout << "\nUnable to open file.\n";
exit(1);
}
string words;
int curLine = 0; //file line counter
while (getline(file, words))
{
++curLine; //counts each line in the file
if (words.find(searchVal) != string::npos)
{
cout << "\nLine " << curLine << " contains " << searchVal << endl;
file.close();
return;
}
else
{
cout << "\nThe value " << searchVal << " was not found.\n";
file.close();
return;
}
}
}
Any help is greatly appreciated

Answer 1

You need to put the else part out side of while loop. Otherwise your function will only search for the first line.

Answer 2

I was bored so I decided to do it too. I'll post mine, even though its already solved. (upvoted the question for the fun of solving ;) )
using namespace std;
int testfile(string filename, int &line, int &character)
{
ifstream is(filename, std::ios::in);
if (!is.is_open()) return 1; //1 = no file
cout << "Search for what value?" << endl;
string value;
cin >> value;
string buf;
while (getline(is,buf))
{
++line;
if (buf.find(value) != buf.npos)
{
character=buf.find(value); //the part that got lost in edit
return 0; //value found, returning 0
}
}
return 2; //return 2 since no value was found
}
which is called under main():
main()
{
int line=0; //what line it is
int character=0; //what character on that line
int result=testfile("test.txt", line, character); //debug+passing as reference
if (result == 1)cout << "could not find file" << endl;
if (result == 2)cout << "could not find value" << endl;
if (result == 0)
cout << "found at line# " << line << " character# " << character << endl;
return 0;
}
Passing values by reference lets us make use of them in our original scope. Therefore the function can both give errors for debugging, and allow useful results for our scopes purpose.
Closing the fstream is not necessary, as leaving the scope will take care of that for us: see here
Hehe, almost like being at school ;)