c++ strings and file input

Question

Ok, its been a while since I've done any file input or string manipulation but what I'm attempting to do is as follows

while(infile >> word) { 
    for(int i = 0; i < word.length(); i++) {
        if(word[i] == '\n') { 
            cout << "Found a new line" << endl; 
            lineNumber++; 
        }

        if(!isalpha(word[i])) {
            word.erase(i);
        }

        if(islower(word[i])) {
            word[i] = toupper(word[i]);         
        }
    }
}

Now I assume this is not working because >> skips the new line character?? If so, whats a better way to do this.

Lara Bailey · Accepted Answer · 2010-05-03 20:43:37Z

9

I'll guess that word is a std::string. When using >>, the first white-space character terminates the 'word' and the next invocation will skip white-space so no white-space while occur in word.

You don't say what you're actually trying to do but for line based input you should consider using the free function std::getline and then splitting each line into words as a separate step.

E.g.

std::string line;
while( std::getline( std::cin, line ) )
{
    // parse line
}

answered May 3, 2010 at 20:43

Lara Bailey

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Comments

Jonathan M Davis · Accepted Answer · 2010-05-03 20:43:15Z

1

How about using getline()?

string line;
while(getline(infile, line))
{
    //Parse each line into individual words and do whatever you're going to do with them.
}

answered May 3, 2010 at 20:43

Jonathan M Davis

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Comments

Anton Kesy · Accepted Answer · 2023-08-23 19:15:52Z

0

There is getline function for istream.

edited Aug 23, 2023 at 19:15

Anton Kesy

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answered May 3, 2010 at 20:43

zvrba

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