Can't find average letters.

[siPeePee]

I can't tell what I'm doing wrong to get the average?

#include <iostream>
#include <cstring>

using namespace std;

int findWhitespace(char[]);
double findAve(char[], int);

int main()
{
	//modified version of Program 12-2...
	const int LENGTH = 80;
	char line[LENGTH];

	cout << "Enter a sentence of no more than ";
	cout << LENGTH - 1 << " characters: " << endl;

	cin.getline(line, LENGTH);
	if (line[0] == ' ' || line[0] == '\0') 
	{

		cout << "Invalid sentence..." << endl;
		cout << "Enter a sentence of no more than ";
		cout << LENGTH - 1 << " characters: " << endl;

		cin.getline(line, LENGTH);

	}//end of if

	int a = findWhitespace(line);

	cout << endl << "The sentence has ";
	cout << a << " words in it." << endl;

	cout << "Average letters per word " << findAve(line, a) << endl;

}//end of main

int findWhitespace(char c[])
{

	int n = 1;//for the first word...

	for (int i = 0; c[i] != '\0'; i++)
	{
		if (c[i] == ' ')
		{
			n++; 
		}
	}

	return n;

}//end of findWhitespace

double findAve(char c[], int words) 
{
	int num, index = 0, letters[words];
	double total, ave;

	for (int j = 0; c[j] != '\0'; j++)
	{
		if (c[j] != ' ' || c[j] != '.') {

			num++;

		} else {

			letters[index] = num;
			index++;
			total += letters[j];
		}
	} 

	ave = total / words;
	return ave;

}//end of findAve 

[jlb]

What are you trying to average? Why are you trying to use variables before they are initialized? Where do you actually assign any values tour letters array?

[siPeePee]

I'm trying to find the average number of letters of words in a sentence.

I thought that I was putting values into letters[index] when the loop came up to "." or " "?

[jlb]

IMO your findAve() function has several major problems. One of the biggest problems is that you're using at least one variable that hasn't been initialized.

Next you're using a VLA in your function, VLA are not allowed in C++ programs. Array sizes must be compile time constants.

Next the use of this array seems inconsistent. You add a value to letters[index] but you "count" letters[j]. These two indexes are not necessarily the same value.

[siPeePee]

Okay, new function works...

int findAve(char c[], int numOfWords, int numOfLetters)
{

        for (int j = 0; c[j] != '\0'; j++)
        {
                numOfLetters++;

                if (c[j] == ' ' || c[j] == '.') {

                        numOfLetters--;

                }
        }

        return numOfLetters / numOfWords;

}//end of findAve 

Is is wrong to create variables inside of functions? That, and what is VLA?

[jlb]

No, it is actually better to create variables inside functions unless the variable contains a value from outside of the function. In your function above you only need to pass the character array since the other two variables are only used inside this function.

A VLA is a Variable Length Array which are only guaranteed to be supported in C99 programs. These constructs allow the creation of arrays with run time sizes. In C++ the alternative is to use a std::vector.

[siPeePee]

We were doing c-strings this week in class so we couldn't use anything we wanted to on the homework. This assignment was supposed to modify the one that came before it.

A lot of the code I see online doesn't use using namespace std; and uses the scope resolution operator on everything. Is that a better standard?

[jlb]

A lot of the code I see online doesn't use using namespace std; and uses the scope resolution operator on everything. Is that a better standard?

IMO, yes using the scope resolution operator is usually a better practice.