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Daily Challenge #3 - Vowel Counter

dev.to staff on June 30, 2019

Hope you’re ready for another challenge! Let’s get started with Day 3. Today’s challenge is modified from user @jayeshcp on CodeWars. Write a ...

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Alvaro Montoro • Jun 30 '19 • Edited

JavaScript:

f=s=>s.match(/[aeiou]/gi).length

Demo on CodePen.

Ryan Smith • Jul 1 '19 • Edited

Nice solution, mine was similar in using regex match, but not as short. This one will error on a string without any vowels because match will return a null which doesn't have a length.

Alvaro Montoro • Jul 1 '19 • Edited

That's a good point. This could be avoided by checking if the result of the match is null and using an empty string instead. Something like this:

f=s=>(`${s}`.match(/[aeiou]/gi)||'').length;

I also used template literals before the match so numeric values or null would be process too... and now the code is even uglier than before :P

K.V.Harish • Oct 3 '19

Typo ${s}

f=s=>(`${s}`.match(/[aeiou]/gi)||'').length;

Alvaro Montoro • Oct 3 '19 • Edited

Good catch! I corrected it. Thank you for letting me know!

Ryland G • Jun 30 '19

I think this is the best solution if you're ok with regex.

Tori Crawford • Jun 30 '19 • Edited

Ruby

Long Solution (my first solution)

def getVowelCount(str)
  vowels = ["a", "e", "i", "o", "u"]
  count = 0
  str.downcase.split('').each do |char|
    vowels.each do |vowel|
      char == vowel ? count += 1 : count += 0
    end
  end 
  count
end

Short Solution (my refactored solution)

def getVowelCount(str)
  str.downcase.count("aeiou")
end

MetaDave 🇪🇺 • Aug 7 '19

It would be interesting to know if str.count("aeiouAEIOU") was faster, or if reordering the letters to try to get the most likely match first was better – e.g. str.count("eiaouEIAOU")

Ryland G • Jun 30 '19 • Edited

const vowelString = 'whatever vowel string';
const count = [...(vowelString.toLowerCase())].map((letter) =>  [...'aeiou'].includes(letter) ? 1 : 0).reduce((aggr, curr) => aggr + curr);

Clay Murray • Jun 30 '19

[...'aeiou'].includes

Ryland G • Jun 30 '19

Fixed, thanks!

Gabi • Jul 18 '19

Hi, i loved this solution. Took me a bit to get my head around the use of reduce here and it's awesome. Thanks. I learned something nice today.

Karthik RP • Dec 18 '19 • Edited

Cool., I didn't know we can use spread on a string. 👍🏻

Ali Spittel • Jul 1 '19

My python solution!

def count_vowels(word):
    return len(l for l in word if l in "aeiou")

protium • Jun 30 '19

Thinking the string as a Set with O(1) for look up operations: solution is O(n), where n = len(str)

def count_vowels(str):
    vowels = "aeiouAEIOU"
    count = 0
    for c in str:
        if c in vowels:
            count += 1
    return count;

JS lambda way

conat vowels = new Set("aeiouAEIOU");
const counVowels = input => [...input].reduce((total, current) => (total += vowels.has(current)), 0);

Shaya • Jul 1 '19 • Edited

Why not so simple as this (JS)...

const vowelsCounter = str => [...str].filter(l => 'aeiouAEIOU'.includes(l)).length;

Ryan Smith • Jun 30 '19 • Edited

Here is my try at it in JavaScript:

/**
 * Count the number of vowels in the input and return an integer.
 */
function countVowels (inputText) {
  // Create a regular expression that matches vowels. Look for all matches (g flag) and ignore case (i flag).
  const vowelRegularExpression = /[aeiou]/gi

  // Convert the input text to lower case and find the matches.
  const vowelMatches = inputText.match(vowelRegularExpression)

  // If there are matches, return the length of the match array. Otherwise, there were no matches, so return 0.
  return (vowelMatches ? vowelMatches.length : 0)
}

Corey Alexander • Jun 30 '19

Oh I've been waiting for this one all morning! Decided I wanted to go all out on this on!

Rust
TDD
AND a Live Stream!

Come check it out while I work my way through this challenge! I'm live now and about to get started!

twitch.tv/coreyja

Corey Alexander • Jun 30 '19

Here is my Rust solution all TDD'ed out!

#[macro_use]
extern crate lazy_static;

pub fn vowel_count(some_string: &str) -> usize {
    lazy_static! {
        static ref VOWELS: Vec<char> = vec!['a', 'e', 'i', 'o', 'u'];
    }

    some_string
        .to_ascii_lowercase()
        .chars()
        .filter(|c| VOWELS.contains(c))
        .count()
}

#[cfg(test)]
mod tests {
    use crate::vowel_count;

    #[test]
    fn it_works_with_an_empty_string() {
        assert_eq!(vowel_count(""), 0);
    }

    #[test]
    fn it_works_non_vowel_strings() {
        assert_eq!(vowel_count("d"), 0);
        assert_eq!(vowel_count("drthpCVM  *&^"), 0);
        assert_eq!(vowel_count("1234567890!@#$%^&*()--__+="), 0);
        assert_eq!(vowel_count("NPlkv.,<>?/"), 0);
    }

    #[test]
    fn it_works_for_strings_of_just_vowels() {
        assert_eq!(vowel_count("a"), 1);
        assert_eq!(vowel_count("A"), 1);
        assert_eq!(vowel_count("AaeEiIoOuU"), 10);
        assert_eq!(vowel_count("eoiuioEAUIAEoieaiAoe"), 20);
    }

    #[test]
    fn it_works_for_mixed_strings() {
        assert_eq!(vowel_count("deadpool"), 4);
        assert_eq!(
            vowel_count("This is just a sentence! With some words and symbols #$%"),
            13
        );
        assert_eq!(vowel_count("TESTING OUT YELLING WITH ALL CAPS"), 9);
        assert_eq!(
            vowel_count("!@#      \nThis is THE MOST COMPLICATED test SoO farrrr"),
            12
        );
    }
}

I'm still live streaming as I type this out, but once I wrap up I'll post a link to the video here!

Corey Alexander • Jun 30 '19 • Edited

Ahhh! :panic:

Turns out OBS didn't want to behave for me today, and split my stream into 2 and dies before I finished, but we got almost all of it recorded! Learnings for next stream!

Links to the video that recorded for the longest here

26:24

Livestream - Dev.to Challenge Vowel Count in Rust

Corey Alexander ・ Jun 30 ・ 1 min read

#challengeanswer #rust #livestream

Benny Powers 🇮🇱🇨🇦 • Jun 30 '19

import { compose } from 'crocks';

const toLowerCase = s => s.toLowerCase();
const spread = s => [...s];
const length = xs => xs.length;
const included = xs => x => xs.includes(x);
const filter = p => xs => xs.filter(p);

const charIncludesCount = chars => compose(
  length,
  filter(included(toLowerCase(chars)),
  spread,
  toLowerCase
);

const vowelCount = charIncludesCount ('aeiou');

Jonathan Kuhl • Jun 30 '19 • Edited

JavaScript, using reduce:

function countVowels(string) {
    const vowels = 'aeiouAEIOU';
    return string.split('').reduce((counter, current) => {
        if(vowels.indexOf(current) != -1) {
            if(counter[current]) {
                counter[current] += 1;
            } else {
                counter[current] = 1;
            }
        }
        return counter;
    }, {});
}

console.log(countVowels('How much wood would a woodchuck chuck if a woodchuck could chuck wood?'));

// { o: 11, u: 7, a: 2, i: 1 }

kesprit • Oct 17 '19

This is my solution in Swift (with an extension 😊) :

extension String {
    func numberOfVowels() -> Int {
        var count = 0
        let vowels: [Character] = ["a","e","i","o", "u", "y"]

        self.lowercased().forEach { char in
            if vowels.contains(char) {
                count += 1
            }
        }

        return count
    }
}

willsmart • Jul 1 '19 • Edited

JS one that's probably pretty speedy

vowelCount = string => {
  let count = 0,
    i;
  for (i = string.length; i > 0; ) {
    const c = string.charCodeAt(--i) & ~0x20; // that's a tilde btw
    count+=Number(c < 70 ? c == 69 || c == 65 : c == 73 || c == 79 || c == 85)
  }
  return count;
};

Note that:

{E:'E'.charCodeAt(0), A:'A'.charCodeAt(0), I:'I'.charCodeAt(0), O:'O'.charCodeAt(0), U:'U'.charCodeAt(0)}

-> {E:69, A:65, I:73, O:79, U:85}

and vowels go pretty much eaiou in terms of how common they are in english.

robbitt07 • Jul 2 '19

Python regex example

import re
def num_vowels(s):
    return len(re.findall('[aeiou]', s))

Timothy Foster • Jun 30 '19 • Edited

TI-Basic Calculator, where the string is in Ans:

sum(seq(0<inString("AEIOUaeiou",sub(Ans,I,1)),I,1,length(Ans

And yes you can omit ending parens, which helps saves some bytes (:

Ilyes Chouia • Aug 23 '19

Here's my solution:
PHP:


function countVowels($string){
    preg_match_all("/[aeiou]/i", $string, $matches);
    return sizeof($matches[0]);
}
echo "Number of vowels : " . countVowels("sUpercalifragilisticexpialidocious");

Michael Lang • Aug 9 '19

Ruby Language

with specs

def vowels str
  str.to_s.scan(/[aeiou]/i).size
end

require "spec"

describe "#vowels" do
  it { expect(vowels nil).to eq 0}
  it { "aeiou".split('').each{|v| expect(vowels v).to eq 1} }
  it { "AEIOU".split('').each{|v| expect(vowels v).to eq 1} }
  it { expect(vowels "foo").to eq 2}
  it { expect(vowels "FOO").to eq 2}
  it { expect(vowels "BCDFG").to eq 0}
  it { expect(vowels "QuEUeInG").to eq 5}
end

output

>> rspec vowels.rb
.......

Finished in 0.00579 seconds (files took 0.14931 seconds to load)
7 examples, 0 failures

Cent • Jan 6 '20

My solution is a bit longer because I don't know regex, but it gets the job done.

CodePen


const countVowels = text => {
  let count = 0;
  text.toLowerCase().split("").forEach(char => {
    if (char === "a" || char === "e" || char === "i" || char === "o" || char === "u")
      count++;
  })
  return count;
}

official_dulin • Sep 8 '20

Go:

package kata

import "strings"

func GetCount(str string) (count int) {
  var vowels = "aeiou"
  for _, v := range str {
    if strings.Contains(vowels, string(v)) {
      count++
    }
  }
  return
}

peter279k • Jun 16 '20

Here is my simple solution with PHP:

function getCount($str) {
  $vowelsCount = 0;

  $vowels = ['a', 'e', 'i', 'o', 'u'];

  $index = 0;
  for(; $index < mb_strlen($str); $index++) {
    if (in_array($str[$index], $vowels)) {
      $vowelsCount += 1;
    }
  }

  return $vowelsCount;
}

Benny Powers 🇮🇱🇨🇦 • Jul 1 '19

Could also

const compose = (...fns) => fns.reduce((f, g) => (...args) => (f(g(...args)));

Ganesh Prasad • Aug 24 '19

const test = require('./tester');
const vowelCount = str => String(str)
    .toLowerCase()
    .split('')
    .filter(ch => 'aeiou'.indexOf(ch) > -1)
    .length;

test(vowelCount, [
    {
        in: ["Hello O'Henry !"],
        out: 4,
    },
    {
        in: ['gnsp'],
        out: 0
    }
]);

E. Choroba • Jul 3 '19

This is very easy in Perl, as the transliteration operator returns the number of matches:

sub vowel_count2 { shift =~ tr/aeiouAEIOU// }

One can also use the Saturn (or Goatse) "secret" operator with a regex match:

sub vowel_count { my $count =()= shift =~ /[aeiou]/gi }

The global match returns all the matches in list context, the assignment to () enforces list context, and enforcing scalar context on it by a scalar assignment returns the number of elements.

Benny Powers 🇮🇱🇨🇦 • Jul 1 '19 • Edited

module Vowels (countVowels) where

import Data.Char (toUpper)

isVowel :: Char -> Bool
isVowel = flip elem "AEIOU"

countChar :: Char -> Integer
countChar letter = if isVowel letter 1 else 0

countVowels :: String -> Integer
countVowels = sum . map (countChar . toUpper)

Will have to double check the syntax (on Mobile) but I think this will work

Peter • Sep 24 '19 • Edited

In go!

func countVowels(s string) int {
    l := strings.ToLower(s)
    count := 0
    for _, c := range l {
        switch c {
        case 'a':
            fallthrough
        case 'e':
            fallthrough
        case 'i':
            fallthrough
        case 'o':
            fallthrough
        case 'u':
            count++
        }
    }
    return count
}

Go playground example

Uses fallthrough mostly because I wanted to, count++ would be smaller, but all cases behave the same (also its more easily maintainable).

moreginger • Jul 1 '19

Haxe

static function vowels(s:String):Int {
  var vowels = 0;
  for (i in 0...s.length) {
    switch (s.charAt(i)) {
      case 'a' | 'A' | 'e' | 'E' | 'i' | 'I' | 'o' | 'O' | 'u' | 'U':
        vowels++;
    }
  }
  return vowels;
}

iterators library looked useful but you can't fold an iterator, only an iterable, disappoint.

jmc • Jun 30 '19 • Edited

You also have to traverse the tree to get to the next letter. But I see what you mean. Only counting equality checks, hard-coding behaves like a linear search. My bad.

I think you might still be missing Brian's point that a hash set has O(1) lookup time, which is faster than the tree set's O(log n).

(On paper. Real-world implementations vary. e.g. Ruby's hashes just do linear search at this size.)

Dylan Paulus • Jun 30 '19 • Edited

Nim

from unicode import toLower

proc countVowels(input: string): int =
  for i in toLower(input):
    if i in "aeiou":
      result += 1

if isMainModule:
  const input = "@PPLes!43"

  echo countVowels(input)

NecroTechno • Jul 1 '19

use regex::Regex;

fn main() {
    let re = Regex::new(r"[aeiou]").unwrap();
    let mut result: i32 = 0;
    for _mat in re.find_iter("Hello, world!") {
        result += 1;
    }
    println!("Vowel count: {:?}", result)
}

Link to playground - play.rust-lang.org/?version=stable...

Ryan Will • Jul 1 '19 • Edited

A solution in Elixir

defmodule VowelCounter do
  @vowels ~r/(a|e|i|o|u)/i
  
  def count(""), do: 0

  def count(string) do
    @vowels 
    |> Regex.scan(string)
    |> Enum.count() 
  end
end

calebefazzani • Jul 1 '19 • Edited

Ruby:

def removeAccents(str)
    accents = {
        ['á','à','â','ä','ã'] => 'a',
        ['é','è','ê','ë'] => 'e',
        ['í','ì','î','ï'] => 'i',
        ['ó','ò','ô','ö','õ'] => 'o',
        ['ú','ù','û','ü'] => 'u'
      }
      accents.each do |ac,rep|
        ac.each do |s|
          str = str.gsub(s, rep)
        end
      end
      str = str.gsub(/[^a-zA-Z0-9\. ]/,"")
      str = str.gsub(/[ ]+/," ")
  str = str.gsub(/ /,"-")
  return str
end


def verifyVowels(texto)
    allLc = removeAccents(texto.downcase);
    countVowels = 0;
    allLc.split("").each do |letra|
        if (letra == 'a') | (letra == 'e') | (letra == 'i') | (letra == 'o') | (letra == 'u')
            countVowels+= 1;
        end
    end
    return countVowels
end

Jarod Smith • Aug 16 '19

function countVowels(string) {
  if(typeof(string) !== 'string')
    throw new Error('input must be a string');

  const vowels = 'aeiouAEIOU';
  let vowelCount = 0;

  for(index in string) {
    if(vowels.includes(string.charAt(index)))
      vowelCount++;
  }
  return vowelCount;
}

ledgible I hope

Kevin Sullivan • Sep 1 '19

const isIncludedIn = <Data>(collection: Data[]) => (value: Data) =>
  collection.includes(value);
const toChars = (input: string) => [...input];
const length = (xs: any[]) => xs.length;
const keepIf = filter => (xs: any[]) => xs.filter(filter);
const pipe = (...fns: Function[]) =>
  fns.reduce((f, g) => (...args) => g(f(...args)));

const detect = (detectableChars: string[]) =>
  pipe(
    toChars,
    keepIf(isIncludedIn(detectableChars)),
    length,
  );

const VOWELS = {
  LOWERCASE: ["a", "e", "i", "o", "u"],
  UPPERCASE: ["A", "E", "I", "O", "U"],
};
const DETECTABLE_LETTERS = [...VOWELS.LOWERCASE, ...VOWELS.UPPERCASE];
export const vowelCounter = detect(DETECTABLE_LETTERS);

Rafi • Sep 19 '19

SQL (Postgres)


\set x 'Hello world'

 select count(*) from                                                                                            
   (select 
     regexp_matches(:'x', '[aeiou]', 'gi')) 
     as vowels;

Adan ϟ • Nov 9 '19

Dart

import 'dart:io';

main(){
  stdout.writeln('Phrase?');
  String phrase = stdin.readLineSync();
  var regExp =  RegExp(r'[aeiou]');
  phrase.length > 2 ? print("Vocal count: " + regExp.allMatches(phrase.toLowerCase()).length.toString()) : print('Invalid Phrase');
}

Peter Bunting • Nov 23 '19

In F#

let isVowel (c:char) =
    match c.ToString().ToLowerInvariant() with
    | "a" | "e" | "i" | "o" | "u" -> 1
    | _ -> 0

let vowelCount (s:string) = s.ToCharArray() |> Array.sumBy(fun x -> isVowel x)

printfn "%d" (vowelCount "The cUnNinG fOx jumpEd over the lazy dog - twice!")

Valerio Narcisi • Nov 13 '19 • Edited

//TS

my solution with TDD:

test:

import vowelCounter from './vowel-counter';

describe('tdd vowel counter', () => {
    test('should be 0 if empty string', () => {
        expect(vowelCounter('')).toEqual(0);
    });
    test('should be return counter', () => {
        expect(vowelCounter('aWscErvO')).toEqual(3);
        expect(vowelCounter('aaaa')).toEqual(4);
        expect(vowelCounter('IIIII')).toEqual(5);
        expect(vowelCounter('AEr#_%^&tioCda')).toEqual(5);
    });
});

and func


export default (str: string): number =>
    str
        .toLowerCase()
        .split('')
        .filter(val => ['a', 'e', 'i', 'o', 'u'].includes(val)).length;

Monica Macomber • Jan 10 '20

A little late to the party, but this is my JavaScript solution:

function vowelCounter(text) {
  const letters = text.toLowerCase().split('');
  const count = [...'aeiou'].map(vowel => 
    letters.filter(letter => letter === vowel)).flat().length;
  return count;
}

David Figueroa • Jan 11 '20

Powershell

I do try to keep it as an actual function and give pretty/usable output.

function Get-VowelCount {
    param(
        [string]$InString
    )

    [pscustomobject]@{
        String              = $InString
        LowerCaseCount = [regex]::Matches($InString,'[aeiou]').Count
        UpperCaseCount = [regex]::Matches($InString, '[AEIOU]').count
    }
}

Jesse Doka • Apr 1 '20 • Edited

Python

def vowelcounter(string):
    i = 0
    string = string.lower()

    for x in string:
        if x in 'aeiou':
            i += 1
    print(i)

vowelcounter("This is a test")

margo1993 • Nov 9 '19 • Edited

func FindVowelsCount(sentence string) int {
    vowels := []string{"a", "e", "i", "o", "u"}
    lowerCaseSentence := strings.ToLower(sentence)

    vowelsCount := 0
    for _, c := range lowerCaseSentence {
        if contains(vowels, string(c)) {
            vowelsCount++
        }
    }

    return vowelsCount
}

func contains(list []string, item string) bool {
    for _, w := range list {
        if w == item {
            return true
        }
    }
    return false
}

Kerri Shotts • Jun 30 '19

const charCounter = ({strToCount = "", chars = ""} = {}) => {
    const charsToCount = chars.toLowerCase();
    return Array.from(strToCount.toLowerCase())
        .reduce((acc, candidate) => acc += charsToCount.includes(candidate) 
        ? 1 : 0, 0)
}

const countVowels= strToCount => charCounter({strToCount, chars: "aeiou"});

assert(countVowels("The quick brown fox jumps over the lazy dog.") === 11);
assert(countVowels("Hello") === 2);
assert(countVowels("Xyl") === 0);
assert(countVowels("aeiouAEIOU") === 10);

mufadhal • Jul 9 '20

}

Martin Himmel • Jul 1 '19

PHP

function count_vowels(string $str) {
    return preg_match_all('/([aeiou])./', strtolower($str));
}

Darrik Moberg • Jul 1 '19

R with some Regex fun:

vowelCounter <- function(s) {
  vowelMatches <- sum(attr(gregexpr("[aeiou]",s, ignore.case = TRUE,
                                    perl= TRUE)[[1]],"match.length"),
                      na.rm = TRUE)
  vowelMatches[vowelMatches == -1 ] <- 0
  return(vowelMatches)
}

Tom Ekander • Jul 3 '19

ReasonML

Sketch: sketch.sh/s/jjxviGaqjQ2P0ZI0SFC2Sg/

let is_vowel = letter =>
  switch (Char.lowercase_ascii(letter)) {
  | 'a'
  | 'e'
  | 'i'
  | 'o'
  | 'u'
  | 'y' => true
  | _ => false
  };

let explode = s => List.init(String.length(s), String.get(s));

let get_vowel_count = text =>
  text |> explode |> List.filter(is_vowel) |> List.length;

get_vowel_count("hello my name is Earl!");

Zapperdulchen • Aug 1 '22

Clojure

(defn count-vowels [s]
  (let [vowels (set "aouei")]
    (->> (clojure.string/lower-case s)
         (filter vowels)
         count)))

(defn count-vowels-2 [s]
  (count (re-seq #"(?i)[aouei]" s)))

Vicente G. Reyes • Jul 1 '19

Python

def vowel(str): 
    count = 0
    vowels = set("aeiouAEIOU") 
    for alphabet in str: 
        if alphabet in vowels: 
            count = count + 1
    print("No. of vowels :", count) 
str = "The Practical Dev"
vowel(str)

Caleb Rudder • Jul 23 '19

C++

int alphaArray [26];

for (int i = 0; i < 26; i++) {
    alphaArray[i] = 0;
}

for (int index = 0; index < userInput.length(); index++) {

    userInput[index] = tolower(userInput[index]);
}

for (int characterIndex = 0; characterIndex < userInput.length(); characterIndex++) {

    alphaArray[userInput[characterIndex] - 97]++;
}

int vowels = alphaArray[0] + alphaArray[4] + alphaArray[8] + alphaArray[14] + alphaArray[20];

cout << "Total number of vowels" << vowels << endl;
cout << "Number of A's: " << alphaArray[0] << endl;
cout << "Number of E's: " << alphaArray[4] << endl;
cout << "Number of I's: " << alphaArray[8] << endl;
cout << "Number of O's: " << alphaArray[14] << endl;
cout << "Number of U's: " << alphaArray[20] << endl;

Héctor Pascual • Aug 7 '19

Python

Given the list :

vowels = ['a', 'e', 'i', 'o', 'u']

We can define a function:

def vowels_count(word):
    count = 0
    for vowel in vowels:
        count += word.lower().count(vowel)
    return count

Or simply in a one-liner:

vowel_count = lambda word: len([char for char in word if char in vowels])

Ceban Dumitru • Jul 1 '19 • Edited

BASH

echo "some STRING 123 (-_-)" | grep -o -i "[aieou]" | wc -l

ListNUX • Jul 3 '19 • Edited

Shell/awk oneliner:

string="Some random string"
awk '{IGNORECASE=1; print gsub(/a|e|i|o|u/, "")}' <<< $string

protium • Jun 30 '19

Not sure if I follow. O(n log n) is worst than O(n). Insertions in a binary tree are expensive to keep it balanced.
If you use a set or hashmap assuming zero collisions, the look up is O(1). Then the bottke neck is in the string iteration. Right?

jmc • Jun 30 '19 • Edited

Clojure:

;; with regex
(defn vowels [s]
  (count (re-seq #"(?i)[aeiou]" s)))

;; without
(defn vowels [s]
  (count (filter #(some #{%} "AaEeIiOoUu") s)))

Dimitri Lahaye • Jul 8 '20

vowels = (str) => (str.match(/[aeiou]/gi) || '').length;

;)

Praneet Nadkar • Jul 16 '19

Using Regex in C#

var vowelCount = Regex.Matches(input, @"[AEIOUaeiou]").Count;

Kamil Biedrzycki • Apr 25 '20

Why there's no y? 🤔

Palash Bauri 👻 • Aug 15 '19

Here comes Another 🚀

Python

def challenge3(s):
    s = s.lower()
    N = 0
    for i in s:
        if i in ["a" , "e" , "i" , "o" , "u"]:
            N += 1
    return N

matej • Feb 1 '20

Java

Objects.requireNonNull(input, "cannot be null");
return Arrays.stream(input.split(""))
   .map(s -> s.toLowerCase())
   .filter(s -> s.matches("[aeiou]"))
   .count();

Siddharth Venkatesan • Dec 26 '19

Ruby

def vowel_count(text)
  text.scan(/([aeiou])/i).size
end


puts vowel_count("Hello World!!!!") #3

Robin Victorino • Jul 9 '19

Groovy has a nice built-in Pattern matcher

Integer countVowels(String text) {
    return (text =~ /(?i)[aeiou]/).size()
}

Josh • Aug 20 '19 • Edited

Rubeh

require 'set'
vwls = %w"a e i o u".to_set

def sm_vwls(strng)
  strng.chars.sum { |c| vwls.include?(c) }
end

Craig McIlwrath • Aug 19 '19

Haskell:

import Data.Char

countVowels :: [Char] -> Int
countVowels = length . filter (`elem` "aeiou" ) . map toLower

cloudyhug • Aug 30 '19 • Edited

Haskell

countVowels :: String -> Int
countVowels = length . filter (flip elem "aeiou")

Andreas Jakof • Sep 24 '19

private static List<char> vowels = new List<char>('e','a','i','o','u','E','A','I','O','U');

public static int VowelCount(this string str) => 
    str.Count(c => vowels.Contains(c));

Kumaravel_Viswam • Mar 27 '20

Python :
def count_vowels(word):
word=word.lower()
data={x:word.count(x) for x in "aeiou"}
return data

Doom Hiker • Jul 4 '19 • Edited

// Java

public static int countVowels(String input) {
return input.length()-input.replaceAll("(?i)[aeiou]", "").length();
}

Harshal Raverkar • Oct 12 '19

var vowelCount = Regex.Matches(str, @"[AEIOUaeiou]").Count;
Console.WriteLine(vowelCount);

jmc • Jun 30 '19 • Edited

We don't care about the vowels being ordered for this problem, so you'd be paying extra time (vs. a hash-based set, or just hard-coded equality checks) for a property you're not using.

useNavigate • Dec 5 '22

Ruby :

def get_count(input_str)
 vowels = 'aeiouAEIOU'
 count = 0
  input_str.each_char do |char|
    count += 1 if vowels.include?(char)
  end
  count
end