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Ongoing Loop

CplusplusHelpPls (4)
On line 39, when I try to test the while loop by entering in only 1 character, the loop goes on forever, and spams all of my black box.
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#include <iostream>
#include <string>
using namespace std;

//prototype
void stateInstructions();
void getString(string&);
void convertToUpper(string);
void convertToLower(string);
void countingVowels(string);
void reverseString(string);

int main()
{
   string userInput;

   stateInstructions();
   getString(userInput);
   convertToUpper(userInput);
   convertToLower(userInput);
   countingVowels(userInput);
   reverseString(userInput);
}

void stateInstructions()
{
   string instructions;
   instructions = "I will be manipulating your text input today.\n";
   cout << instructions;
}

void getString(string &userInput)
{
   string instructions;
   instructions = "Please enter anything with at least 4 characters.\n";
   cout << instructions;
   //get userinput
   getline(cin, userInput);
   while (userInput.length() <= 4)
      cout << "Please enter more than 4 characters." << endl;
   cout << "You have entered this as your input: " << userInput << endl;
}

void convertToUpper(string userInput)
{
   string response;
   response = "This is your input in all capital letters: ";
   // string convertToUpper(userInput);
   for (int i = 0; userInput[i]; i++)
      userInput[i] = toupper(userInput[i]);
   cout << response << userInput << endl;
}

void convertToLower(string userInput)
{
   string response;
   response = "This is your input in all lower case letters: ";
   for (int i = 0; userInput[i]; i++)
      userInput[i] = tolower(userInput[i]);
   cout << response << userInput << endl;
}

void countingVowels(string userInput)
{
   string response;
   // Counting Vowels
   int numOfVowels = 0;
   response = "The number of vowels in your input line: ";
   for (int i = 0; i < userInput.length(); i++)
   {
      if (userInput[i] == 'a' || userInput[i] == 'e' || userInput[i] == 'i' || userInput[i] == 'o'
         || userInput[i] == 'u' || userInput[i] == 'A' || userInput[i] == 'E' || userInput[i] == 'I'
         || userInput[i] == 'O' || userInput[i] == 'U')
         numOfVowels++;
   }
   cout << response << numOfVowels << endl;
   //Counting Spaces
   int numOfSpaces = 0;
   for (int i = 0; i < userInput.length(); i++)
   {
      if (userInput[i] == ' ')
         numOfSpaces++;
   }
   // Counting Numbers
   int numOfNumbers = 0;
   for (int i = 0; i < userInput.length(); i++)
   {
      if (userInput[i] == '1' || userInput[i] == '2' || userInput[i] == '3' || userInput[i] == '4'
         || userInput[i] == '5' || userInput[i] == '6' || userInput[i] == '7' || userInput[i] == '8'
         || userInput[i] == '9' || userInput[i] == '0')
         numOfNumbers++;
   }
   // Counting Punctuation
   int numOfPunc = 0;
   for (int i = 0; i < userInput.length(); i++)
   {
      if (userInput[i] == ',' || userInput[i] == '?' || userInput[i] == '!' || userInput[i] == '/'
         || userInput[i] == '@' || userInput[i] == '#' || userInput[i] == '$' || userInput[i] == '%'
         || userInput[i] == '^' || userInput[i] == '&' || userInput[i] == '*' || userInput[i] == '('
         || userInput[i] == ')' || userInput[i] == '-' || userInput[i] == '=' || userInput[i] == '_'
         || userInput[i] == '+' || userInput[i] == '`' || userInput[i] == '~' || userInput[i] == '<'
         || userInput[i] == '>' || userInput[i] == '.' || userInput[i] == '"' || userInput[i] == '"')
         numOfPunc++;
   }

   // Counting Consonants
   response = "There are these many consonants in your input line: ";
   int size = userInput.length() - numOfSpaces - numOfNumbers - numOfPunc;
   int numOfCons = size - numOfVowels;
   cout << response << numOfCons << endl;
}

void reverseString(string userInput)
{
   string response;
   // Text Manipulation - Reversing
   response = "This would be your input line all reversed: ";
   string reverse(userInput);
   userInput = string(userInput.rbegin(), userInput.rend());
   cout << response << userInput << endl;
}
Last edited on
Ispil (788)
You never try to get the user input again from within the while loop. You check if the user input is less than four, tell them that it is less than four, then check if it is less than four.
CplusplusHelpPls (4)
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   do
   {
      cout << "Please enter more than 4 characters."
         "\nPlease try again." << endl;
      getline(cin, userInput);
   } while (userInput.length() <= 4);


I tried that, but now I can't enter more than like 7 characters
Last edited on
Atyab (51)
If you enter only one character then userInput.length() will be 1 and since 1 is less than 4, this statement cout << "Please enter more than 4 characters." << endl; will be executed without any limits (Infinite Loop)

As Ispil mentioned, you can do something like this:

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getline(cin, userInput);

while (userInput.length() <= 4)
{
    cout << "Please enter more than 4 characters." << endl;
    getline(cin, userInput);
}


OR 

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do
{
    getline(cin, userInput);
    
    if(userInput.length() <= 4)
        cout << "WARNING: Please enter more than 4 characters." << endl;

} while(userInput.length() <= 4);
CplusplusHelpPls (4)
I used the first one and it worked, but not the second one. Weird. Thanks everyone! :)
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