JavaScript: Count the number of vowels in a given string

Last update on May 30 2022 10:02:07 (UTC/GMT +8 hours)

JavaScript validation with regular expression: Exercise-8 with Solution

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

Test Data:
console.log(alphabetize_string('United States'));
Output :
"SUadeeinsttt"

Pictorial Presentation:

JavaScript: Count the number of vowels in a given string

Sample Solution:-

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Write a JavaScript function to count the number of vowels in a given string</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function vowel_count(str) {

  return str.match(/[aeiou]/gi).length;

}

console.log(vowel_count('The quick brown fox jumps over the lazy dog'));

Sample Output:

Flowchart:

Live Demo:

See the Pen javascript-regexp-exercise-8 by w3resource (@w3resource) on CodePen.

Improve this sample solution and post your code through Disqus

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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