JavaScript: Count the number of vowels in a given string

Last update on May 30 2022 10:06:57 (UTC/GMT +8 hours)

JavaScript Basic: Exercise-54 with Solution

Write a JavaScript program to count the number of vowels in a given string.

Pictorial Presentation:

JavaScript: Count the number of vowels of a given string

Sample Solution:

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JavaScript program to count the number of vowels in a given string.</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function vowel_Count(str)
{ 

  return str.replace(/[^aeiou]/g, "").length; 
}

console.log(vowel_Count("Python"));
console.log(vowel_Count("w3resource.com"));

Sample Output:

1
5

Flowchart:

ES6 Version:

function vowel_Count(str)
{ 

  return str.replace(/[^aeiou]/g, "").length; 
}

console.log(vowel_Count("Python"));
console.log(vowel_Count("w3resource.com"));

Live Demo:

See the Pen JavaScript - count the number of vowels in a given string - basic-ex-54 by w3resource (@w3resource) on CodePen.

Contribute your code and comments through Disqus.

Previous: Write a JavaScript program to check if the characters a and b are separated by exactly 3 places anywhere (at least once) in a given string.
Next: Write a JavaScript program to check if a given string contains equal number of p's and t's present.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.

JavaScript: Tips of the Day

How to insert an item into an array at a specific index (JavaScript)?

What you want is the splice function on the native array object.

arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert). In this example we will create an array and add an element to it into index 2:

var arr = [];
arr[0] = "Jani";
arr[1] = "Hege";
arr[2] = "Stale";
arr[3] = "Kai Jim";
arr[4] = "Borge";

console.log(arr.join());
arr.splice(2, 0, "Lene");
console.log(arr.join());

Ref: https://bit.ly/2BXbp04