JavaScript: Check a given number is an ugly number or not

Last update on April 22 2023 12:21:22 (UTC/GMT +8 hours)

JavaScript Math: Exercise-100 with Solution

Write a JavaScript program to check if a given number is ugly.

Ugly numbers are positive numbers whose only prime factors are 2, 3 or 5. The first 10 ugly numbers are:
1, 2, 3, 4, 5, 6, 8, 9, 10, 12, ...
Note: 1 is typically treated as an ugly number.

Visualisation:

$JavaScript Math: Check a given number is an ugly number or not.$

Test Data:
(12) -> true
(18) -> true
(19) -> false

Sample Solution:

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JavaScript program to Check a given number is an ugly number or not</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function test(n) {
  map = [5, 3, 2];
  for (let i = 0; i < map.length && n > 1; i++) {
    while (n % map[i] === 0) n /= map[i];
  }
  return n === 1;
};  
n = 12
console.log("n = " +n)
console.log("Check the said number is an ugly number? "+test(n));
n = 18
console.log("Original text: " +n)
console.log("Check the said number is an ugly number? "+test(n));
n = 19
console.log("Original text: " +n)
console.log("Check the said number is an ugly number? "+test(n));

Sample Output:

n = 12
Check the said number is an ugly number? true
Original text: 18
Check the said number is an ugly number? true
Original text: 19
Check the said number is an ugly number? false

Flowchart:

$JavaScript: Add digits until there is only one digit.$

Live Demo:

See the Pen javascript-math-exercise-100 by w3resource (@w3resource) on CodePen.

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