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C Program To Count Frequency Of Vowels

    The C program to count the frequency of vowels, consonants and white spaces for a given word or a sentence is a string manipulation program. A C loop with conditions that checks the given input string and count the number of vowels, consonants, and white spaces.

    We compiled this program using Dev-C++ compiler installed on a Windows 7 64-bit system. You may try another standard C compiler and to get an error free program make necessary changes to the source code.

    Also, before you try this example, learn following C programming concepts. If you are familiar with them, continue reading.

    Problem Definition

    In C language every string is like an array with each character of the string hold a position in this array. The last character is null character by default.

    Using this array logic, the program read a word or a sentence during execution and check each and every character of input string. It counts the number of vowels, consonants and white spaces.

    For example, the array representation of word – SPIDERMAN as follows.

    \begin{aligned} &0 \hspace{5px}1  \hspace{5px}2\hspace{5px} 3 \hspace{5px}4 \hspace{5px}5 \hspace{5px}6\hspace{5px} 7\hspace{5px} 8 \hspace{5px}9 \\ 
    &S \hspace{3px} P\hspace{3px} I \hspace{3px}D \hspace{3px}E \hspace{3px}R \hspace{3px}M\hspace{3px} A \hspace{3px}N \hspace{3px}\backslash\empty\end{aligned}

    Note:- The Null character is added to all the strings in C by default.

    Flowchart – Program to Count Frequency of Vowels

    Flowchart - C Program to count the frequency of Vowels.
    Flowchart – C Program to count the frequency of Vowels.

    Program Code – Program to Count Frequency of Vowels

    /*Read a sentence and print frequency of each vowels and the total count of consonants */
    #include <stdio.h>
    #include <conio.h>
    int main()
    {
        char str[100];
        int a,e,i,o,u,consonant,whitespace;
        a = e = i = o = u = consonant = whitespace = 0;
        int k;
        /* Get the Sentence */
        gets(str);
        /* read the sentence */
        for(k=0;k<strlen(str);k++) 
        { 
            if(str[k]== 'a') 
            { 
                a = a+1; 
            } 
            else if(str[k] == 'e') 
            { 
                e = e +1; 
            } 
            else if(str[k] == 'i') 
            { 
                i = i +1; 
            } 
            else if( str[k] == 'o') 
            { 
                o = o + 1; 
            } 
            else if(str[k] == 'u') 
            { 
                u = u+1; 
            } 
             else if((str[k] >= 'a' && str[k] <= 'z')||(str[k] >= 'A' && str[k] <= 'Z'))
            {
                consonant ++;
            }
            else if (str[k] == ' ')
            {
                whitespace++;
            }
        }
        printf("a :%d\n",a);
        printf("e :%d\n",e);
        printf("i :%d\n",i);
        printf("o :%d\n",o);
        printf("u :%d\n",u);
        printf("Consonant :%d\n",consonant);
        printf("whitespace :%d\n",whitespace);
        /* count vowels and consonants */
        /* print the results */
        system("PAUSE");
        return 0;
    }

    Apart from being a string program, we used built-in functions from C standard library to get string input (gets) and compute the length of the given input string (strlen).

    Output

    The output of the program is given below. When the sentence ” A large reptile” is entered, the program reads all the vowels, consonants and white spaces and print the results.

    ENTER A WORD OR A SENTENCE:
    A large reptile
    _____________________________________________
    a :1
    e :3
    i :1
    o :0
    u :0
    
    CONSONANTS :8
    WHITESPACES :2