Let’s write a C program to find the frequency of vowels in a string. This program will ask the user to enter a string, read it and print out the count of each vowel. The calculation will be case-insensitive i.e. the vowel can be either upper case or lower case.
Algorithm :
We will use the below algorithm in this program :
- Ask the user to enter a string.
- Initialize five different variables to store the count of each vowel.
- Iterate through the characters of that string one by one.
- Check for each character, if it is a vowel or not. Also, check which vowel it is.
- Increment the count for that corresponding vowel.
C program :
#include <stdio.h>
int main()
{
char strArr[100];
int count_a = 0, count_e = 0, count_i = 0, count_o = 0, count_u = 0;
printf("Enter a string : ");
fgets(strArr, 100, stdin);
int i = 0;
while (strArr[i] != '\0')
{
switch (strArr[i])
{
case 'a':
count_a++;
break;
case 'A':
count_a++;
break;
case 'e':
count_e++;
break;
case 'E':
count_e++;
break;
case 'i':
count_i++;
break;
case 'I':
count_i++;
break;
case 'o':
count_o++;
break;
case 'O':
count_o++;
break;
case 'u':
count_u++;
break;
case 'U':
count_u++;
break;
}
i++;
}
printf("Count of A : %d\nCount of E : %d\nCount of I : %d\nCount of O : %d\nCount of U : %d\n", count_a, count_e, count_i, count_o, count_u);
return 0;
}Explanation :
Below are the explanation for the above program :
- strArr is a character array of size 100. This character array is used to hold the user input string.
- This program is taking the user input string using fgets and storing that value in strArr.
- Using a while loop, we are iterating through the characters one by one.
- Also, we are using one switch-case block to check the current iterating character. It checks if the character is a vowel or not. If it is a vowel, it increments the counter for that vowel.
- If the current character is not vowel, it will not execute the switch-case block.
- Finally, we are printing out the count of each vowel.
Sample Output :
Enter a string : hello world
Count of A : 0
Count of E : 1
Count of I : 0
Count of O : 2
Count of U : 0
Enter a string : The quick brown fox jumps over the lazy dog
Count of A : 1
Count of E : 3
Count of I : 1
Count of O : 4
Count of U : 2