help on string

[k2k]

I need to let the user input a line of words and make all the 4 letter words in the sentence "love"....

example:
cin>> I hate programming

output --> I love programming

does anybody know if there is any library, or string member functions would help doing this task?

below is so far what i have, i have a function to return the index of the space... I don't know what else i can do.

# include <iostream>
# include <string>
using namespace std;
int indexCounter(string sentence, int startingIndex);

int main()
{
	string line;
	int startIndex=0;
	int endIndex=0;
	int size= line.size();
	
	cout<<"Please enter a sentence."<<endl;
	getline(cin,line);




	return 0;
}



int indexCounter(string sentence, int startIndex, int& endIndex)
{
	for(int i=startingIndex; i<size; i++)
	{
		if(sentence[i]==' ')
		{
			return i;  //white space index
		}
		endIndex=i;
		
	}
}

[VernonDozier]

How about if you create a function that takes a large string (i.e. the user inputted sentence string named "line") and returns a vector of smaller strings? Each string in the vector would be a word. Something like this:

vector <string> ParseIntoWords (string sentence);

So in your example, you pass this function the string "I hate programming" and it returns a vector of three strings:

I
hate
programming

The function you have could help parse out the separate words, as could the function "isspace" from the cctype library: http://www.cplusplus.com/reference/clibrary/cctype/isspace.html

Also potentially useful could be this function:
http://www.cplusplus.com/reference/string/string/substr.html

You could then go through this vector of strings and check to see whether a string had four letters. If so, change the string. You end up with a vector like this:
I
love
programming

Concatenate the above vector of strings and you have your revised string (except from the period. Also you may have to put the spaces back in).

[WaltP]

Use .find() to find the spaces. If you find 2 spaces with 4 characters between them, use .replace() to replace the 4 characters.

And remember, the end of the sentence may not end in a space, but it may end in a 4-letter word.