Count the number of vowels in a string Program to Count the Number of vowels we’re going to check how many vowels are present in a given String . There are five vowels in English vocabulary, they are – ‘a’, ‘e’, ‘i’, ‘o’, ‘u’.

For Example, in the string prepinsta then in that case then vowesl are 3 (a,e,i)

Program count the number of vowels in a string Algorithm Step 1:- Start. Step 2:- Take user input. Step 3:- Initialize count variable. Step 4:- Iterate through the string to find number of vowels. Step 5:- Check if the alphabet of the string lies under the group of vowels. Step 6:- If TRUE increment count by 1. Step 7:- Print count. Step 8:- End. Python program to count number of vowels in a string Run #take user input String = input('Enter the string :') count = 0 #to check for less conditions #keep string in lowercase String = String.lower() for i in String: if i == 'a' or i == 'e' or i == 'i' or i == 'o' or i == 'u': #if True count+=1 #check if any vowel found if count == 0: print('No vowels found') else: print('Total vowels are :' + str(count)) Output: Enter the string :PrepInsta Total vowels are :3 Note The time complexity of above code in O(n) as in the code we are looping over the sting once Method 2 Objective: Find number of vowels in string python

First take the string input in a string variable and make a function countVowels(str,str.length()) if the value of n that is (length of the string) is 1 then we will return. (This is the base case) if the size of the string is not 1 then countVowels(str, n-1) + isVowel(str[n-1]) Here isVowel(str[n-1]) will be called if the character is vowel then this will return 1 otherwise 0 Program count the number of vowels Objective: Given an alphabetical string ‘s’. count the number of vowels in it.

Run

Function to check the Vowel

def isVowel(ch): return ch.upper() in ['A', 'E', 'I', 'O', 'U']

to count total number of

vowel from 0 to n

def countVovels(str, n): if (n == 1): return isVowel(str[n - 1]); return (countVovels(str, n - 1) + isVowel(str[n - 1]));

Driver Code

string object

str = "prepinsta";

Total numbers of Vowel

print("Total numbers of Vowel =",countVovels(str, len(str))) Total numbers of Vowel = 3