Counting number of vowels in a string

[davtk8]

I want to count all the vowels in a string (a, e, i , o, u) and display it as a text-based histogram for example:

[INPUT] The black cat sat up on the orange mat!

[OUTPUT]
A: *****
E: ***
I:
O: **
U: *

The asterisks are supposed to correspond to the number of vowels that are counted (using increments and the function setfill()).

 #include <iostream>
#include <string>
#include <iomanip>
using namespace std;


void calculateVowels(string text, int a_vowel, int e_vowel, int i_vowel, int o_vowel, int u_vowel)
{

	int a(0), e(0), i(0), o(0), u(0);
	for (int c = 1; c <= text.size(); c++)
	{
		if (text[c] == 'a')
			{a++;}
		else if (text[c] == 'e')
			{e++;}
		else if (text[c] == 'i')
			{i++;}
		else if (text[c] == 'o')
			{o++;}
		else if (text[c] == 'u')
			{u++;}
		
	}
	a_vowel = a, e_vowel = e, i_vowel = i, o_vowel = o, u_vowel = u;
}

int main()
{
	string text;
	cout << "Enter some text:" << endl;
	getline(cin, text);
	int a(0), e(0), i(0), o(0), u(0), non_space_characters;
	calculateVowels(text, a, e, i , o , u);
	cout << text << " " << a << " " << e << " " << i << " " << o << " " << u << endl;
		cout << "A:" << setfill('*') << setw(a) << endl;
		cout << "E:" << setfill('*') << setw(e) << endl;
		cout << "I:" << setfill('*') << setw(i) << endl;
		cout << "O:" << setfill('*') << setw(o) << endl;
		cout << "U:" << setfill('*') << setw(u) << endl;
	system("PAUSE");
		   return 0;
}

This is my output during compilation:

[OUTPUT]
The black cat sat up on the orange mat! 0 0 0 0 0
A:
E:
I:
O:
U:

[wildblue]

If you pass the variables by reference, the totals will update back in main. Right now you're only incrementing locally in the separate function.

[megatron 0]

for (int c = 1; c <= text.size(); c++)
	{
		if (text[c] == 'a')
			{a++;}
		else if (text[c] == 'e')
			{e++;}
		else if (text[c] == 'i')
			{i++;}
		else if (text[c] == 'o')
			{o++;}
		else if (text[c] == 'u')
			{u++;}
		
	}

Arrays start at 0 not 1;


for (int c = 0; c < text.size(); c++)

The second thing:

int a_vowel, int e_vowel, int i_vowel, int o_vowel, int u_vowel

It can be confusing when passing arguments, that when done like this, you make a copy of the variable, if you want to pass it so any data manipulated is not local, then pass it by reference.

int& a_vowel, int& e_vowel, int& i_vowel, int& o_vowel, int& u_vowel

Let me know how it goes.

[wildblue]

The fill is putting the asterisks at the front of each line, which isn't what you intend. Does the assignment require you use setfill()?

[davtk8]

[OUTPUT]
aeiou 1 1 1 1 1
A:
E:
I:
O:
U:

It's not outputting the asterisks, in this case it should be one * for all the vowels

A: *
E: *
I: *
O: *
U: *

  #include <iostream>
#include <string>
#include <iomanip>
using namespace std;


void calculateVowels(string text, int& a, int& e, int& i, int& o, int& u)
{
	for (int c = 0; c < text.size(); c++)
	{
		if (text[c] == 'a')
			{a++;}
		else if (text[c] == 'e')
			{e++;}
		else if (text[c] == 'i')
			{i++;}
		else if (text[c] == 'o')
			{o++;}
		else if (text[c] == 'u')
			{u++;}
		
	}
}

int main()
{
	string text;
	cout << "Enter some text:" << endl;
	getline(cin, text);
	int a(0), e(0), i(0), o(0), u(0), non_space_characters;
	calculateVowels(text, a, e, i , o , u);
	cout << text << " " << a << " " << e << " " << i << " " << o << " " << u << endl;
		cout << "A:" << setfill('*') << setw(a) << endl;
		cout << "E:" << setfill('*') << setw(e) << endl;
		cout << "I:" << setfill('*') << setw(i) << endl;
		cout << "O:" << setfill('*') << setw(o) << endl;
		cout << "U:" << setfill('*') << setw(u) << endl;
	system("PAUSE");
		   return 0;
}

[davtk8]

My assignment does not state to use this function, but I have to some how get it output a histogram for each vowels counted.

[wildblue]

You could use a loop that outputs a * according to the vowel count.

[davtk8]

Could I just instead of incrementing each vowel, concatenate * by changing from int to string so I don't need setfill and setw

[davtk8]

 #include <iostream>
#include <string>
#include <iomanip>
using namespace std;


void calculateVowels(string text, string& a, string& e, string& i, string& o, string& u)
{
	for (int c = 0; c < text.size(); c++)
	{
		if (text[c] == 'a')
			{a += '*';}
		else if (text[c] == 'e')
			{e += '*';}
		else if (text[c] == 'i')
			{i += '*';}
		else if (text[c] == 'o')
			{o += '*';}
		else if (text[c] == 'u')
			{u += '*';}
		
	}
}

int main()
{
	string text;
		char prev;
	cout << "Enter some text:" << endl;
	getline(cin, text);
		string a, e, i, o, u, non_space_characters;

	calculateVowels(text, a, e, i , o , u);

		cout << "A:" << a << endl;
		cout << "E:" << e << endl;
		cout << "I:" << i << endl;
		cout << "O:" << o << endl;
		cout << "U:" << u << endl;	
	system("PAUSE");
		   return 0;
}

This way works!

[wildblue]

That works too.

You're only counting lower case? What if it were "A black cat..." instead of "The black cat..."

[davtk8]

I know, also I need to program it to count the letters (excluding the spaces) that are NOT vowels.

[INPUT]
the black cat sat up on the orange mat!
[OUTPUT]
A: *****
E: ***
I:
O: **
U: *
Other (non-space) Characters: 20

[megatron 0]

also I need to program it to count the letters (excluding the spaces) that are NOT vowels.

for (int c = 0; c < text.size(); c++)
	{
		if (text[c] == 'a')
			{a += '*';}
		else if (text[c] == 'e')
			{e += '*';}
		else if (text[c] == 'i')
			{i += '*';}
		else if (text[c] == 'o')
			{o += '*';}
		else if (text[c] == 'u')
			{u += '*';}
		else if(text[c] == ' ')
                {
                        continue;
                }
                else nonvowel += '*'
	}

[davtk8]

I want to display it as a number:

Other (non-space) Characters: 20

[davtk8]

Or could I just do nonvowel.size() before outputting?

[megatron 0]

Or could I just do nonvowel.size() before outputting?

Try it. :)

[davtk8]

It works! Thanks for your assistance!

 #include <iostream>
#include <string>
#include <iomanip>
using namespace std;


void calculateVowels(string& text, 
					 string& a, string& e, string& i, string& o, string& u,
					 string& nonvowel)
{


	for (int c = 0; c < text.size(); c++)
	{
		if (text[c] == 'a')
			{a += '*';}
		else if (text[c] == 'e')
			{e += '*';}
		else if (text[c] == 'i')
			{i += '*';}
		else if (text[c] == 'o')
			{o += '*';}
		else if (text[c] == 'u')
			{u += '*';}
		else if (text[c] == ' ')
		{continue;}
		else 
		{nonvowel += '*';}
	}
}

int main()
{
	string text, a, e, i, o, u, nonvowel;
	cout << "Enter some text:" << endl;
	getline(cin, text);
	
	calculateVowels(text, a, e, i , o , u, nonvowel);
		cout << "A:" << a << endl;
		cout << "E:" << e << endl;
		cout << "I:" << i << endl;
		cout << "O:" << o << endl;
		cout << "U:" << u << endl;	
		cout << "Other (non-space) Characters: " << nonvowel.size() << endl;

	system("PAUSE");
    return 0;
}

[davtk8]

One last question. What does 'continue;' do exactly or I'm I stating the obvious?

[megatron 0]

Excellent work!

Now why don't you try and refactor your code a little? Make it tidier maybe? An extra function?

The keyword continue does exactly that, while in a loop such as that it skips to the end of the iteration, ready for the incrementation and the loop starts again, if that makes sense? Just think of it as a quicker iteration.

However the way it is used in that loop, taking it out would have no effect, the if will be called with an empty body, no code to process, skip to the next iteration.


I am glad to help. If you have any other queries, please let me know.

[davtk8]

How and where do use tolower() function, when converting all characters in a string to lowercase?

[davtk8]

Could I just simply use || in the condition state of my sub-routine?

For example:

if (text[c] == 'a' || text[c] == 'A')
{a += '*';}