find percentage of letter 'b' in words read from cin

[fmunoz314]

Hey all. i need to write a program that will read words in from cin until the word stop is entered. Then output the percentage of the letter 'b' contained in all the words read as a floating point number (excluding the word stop). Its not really working though. I keep getting zero. maybe you guys can shed some light. Thanks! Oh and were only allowed to use if/else statements and loops.

	float partSum;
	float count=0;
	float totalSum=0;
	float percentage=0;
	string word;
	string endProgram= "stop";
	cout << "To end program enter 'stop'" << endl << "Enter a word: ";
	cin >> word;
	while (word != endProgram)
	{
		word.find('b');						// finds out if it has b?							
		if (string::npos)																																					
			count;									// does nothing																	
		else
		{
			count++;								//adds to counter
		}																		
		partSum=word.size();						// gets num of letters in word	
		totalSum= (partSum + totalSum);
		percentage= (count/totalSum);				//gives the percentage of time 'b' occurs			
		cout<< "Enter another word:";				// so it keeps asking for new words
		cin >> word;								
		
	}
	
	cout<< "Thee percentage of the letter 'b' contained in all the words is " << percentage << endl;

[rafae11]

if you want to assign a value to a variable you need to use =.

== is for comparison.

for example

result = 5 + 5;

result will now have a value of 10;

result == (5 + 5)

you are comparing result to the value on the right.

[MiiNiPaa]

'b'||'B'

|| is a logical operator. It expect both operands to be boolean values and returns a boolean. For backward compatibility reasons bool can be freely converted to and from integral types which char is one of. Any non-zero value is converted true, so that code can be rewritten as true || true. It is obviously true, which can be converted to the character '\0x01', which is unlikely to be encountered in text file. So line word.find('b'||'B'); will always return std::string::npos.

[fmunoz314]

Thanks guys! this is helping a lot!
Fixed the equals sign. That make sense.
How would I fix the || issue? would i write two pieces? one for b and another for B? I was just trying to simplify it by using ||

[tipaye]

line 11 doesn't do what you think, 'b'|| 'B' is a boolean, in this case true. You're searching for boolean true in your string. It's the same as trying word.find(true);
lines 12 and 11 indeed does nothing. string::npos is not a condition, it's a literal, returned from string::find(), what you've done is the same as saying if(3)
In fact, in that while loop, the only statements that have any effect are lines 18, 21 and 22.

== is not the same as =, and if it were, lines 19 and 20 would still be wrong.
= assigns the value of whatever is on the right to whatever is on the left. The result is the value assinged
== compares the value on the right to the value on the left, the result is either true or false.
A lot of unnecessary variables and type abuse.

I've made a few modifications, as a learning venture, enough to point out some (not all) the problems, and deliver a program that builds, and runs correctly. You'll have to find and fix the others yourself, you'll also have to handle istream errors yourself.

#include <iostream>
#include <string>
#include <cctype>

using namespace std;

string LowerCase(const string &str)
{
	string lc("");
	for (auto &c : str) lc += tolower(c);
	return lc;
}

int main()
{
	size_t count=0;
	size_t totalSum=0;
	string word;
	const string endProgram("stop");
	cout << "To end program enter '" << endProgram << "'" << endl << "Enter a word: ";
	cin >> word;
	while (word != endProgram)
	{
		string lcWord = LowerCase(word); // convert word to lower case
		size_t pos = lcWord.find('b');
		while (string::npos != pos)
		{
			++count; // find all occurrences of 'b' in sword
			pos = lcWord.find('b', pos + 1);
		}
		
		totalSum += word.size();						// accumulates num of letters in word	
		cout<< "Enter another word:";				// so it keeps asking for new words
		cin >> word;								
	}
	
	double percentage = (count * 100.0) / totalSum;
		//gives the percentage of time 'b' occurs			
		
	
	cout<< "The percentage of the letter 'b' contained in all the words is " << percentage << endl;
}

Edit:
This might seem obvious but...

h and were only allowed to use if/else statements and loops.

If you're not allowed a function or ranged for, then inline the code and use a traditional for loop. Be careful about out-of-bounds indexing