Question

#include <iostream>
#include <cstring>
#include <string>
#include <istream>

using namespace std;

//Function prototypes
int numVowels(char *str);
int numConsonants(char *str);

int main()
{
   char string[100];
   char inputChoice, choice[2];
   int vowelTotal, consonantTotal;

   //Input a string
   cout << "Enter a string: " << endl;
   cin.getline(string, 100);
  
   do
   {
       //Displays the Menu
       cout << "   (A) Count the number of vowels in the string"<<endl;
       cout << "   (B) Count the number of Consonants in the string"<<endl;
       cout << "   (C) Count both the vowels and consonants in the string"<<endl;
       cout << "   (D) Enter another string" << endl;
       cout << "   (E) Exit program" << endl;

       //Inputting choice
       cout << "Enter choice: ";
       cin.getline(choice, 2);
       inputChoice = choice[0]; //a single char variable will now equal the choice user pic from c-string
       switch (toupper(inputChoice)) //a switch case, any user input char that is lower case will be now uppercase
       {
           case 'A'://Function call to get number of Vowels
               vowelTotal = numVowels(string);
               cout << "Number of vowels is: " << vowelTotal << endl;
           break;

           case 'B': //Function call to get number of consonants
               consonantTotal = numConsonants(string);
               //Outputting number of Consonants
               cout << "Number of Consonants is: " << consonantTotal << endl;
           break;

           case 'C': //Function call to get number of Vowels
               vowelTotal = numVowels(string);
               //Function call to get number of consonants
               consonantTotal = numConsonants(string);

               //Outputting Both Vowels and Consonants
               cout << "Number of vowels is: " << vowelTotal << endl;
               cout << "Number of Consonants is:" << consonantTotal << endl;
           break;

           case 'D': //Inputting another string
               //Input a string
               cout << "Enter a string: " << endl;

               cin.getline(string, 100);
           break;

           case 'E': exit(0);
           break;

       }//End of Switch

   } while (inputChoice != 'E');//End Do while

}//End main

//Function Definitions
int numVowels(char *str)

{
   int count = 0;//Local variable accumulates the total number of vowels
   while (*str != '\0')
   {
       if (*str == 'a' || *str == 'e' || *str == 'i' || *str == 'o' || *str == 'u')
           count++;
           str++;
   }//End While

   //Returns count value to function call
   return count;
}

int numConsonants(char *str)
{
   int count = 0;
   //Checks for all characters in C-string

   while (*str != '\0')

   { //Checks for consonants
       if (*str != 'a' && *str != 'e' && *str != 'i' && *str != 'o' && *str != 'u')
       count++;
       str++;
   }//End While

   //Returns count value to function call
   return count;
}

This is the code to my homework probably. the Program works but the problem is that if i enter more than 100 chars my program will crash because of my array setting. how would i set it to where i can input any amount of chars and wouldn't worry about the set limit. is there away to dynamically allocate memory for cstrings? Thank you.

Answer 1

Instead of dynamically allocating, We can increase the size of the character array. Your program is correct. We need change the size of the character array in the program. In the following screen shots you can see. I changed the size of the character array to 1000. It means it can store upto 1000 characters. If we want more size we can increase the size of the character array. In dynamic allocate we need to specify the memory we need to use malloc,calloc for allocating space. And we need to use free function for realeasing of memory. Instead of doing all this work we can increase the size of character array.

INPUT:

In the first input i entered 104 characters. It is executed. And in the second output i entered more than 104 characters. Just we need to increase the size of character array.That's it.