Finding pandigital numbers using JavaScript

A pandigital number is a number that contains all digits (0-9) at least once. In this tutorial, we'll create a JavaScript function to check if a given number string is pandigital.

What is a Pandigital Number?

A pandigital number must contain every digit from 0 to 9 at least once. For example, "1234567890" is pandigital, while "123456789" is not (missing 0).

Example

Let's implement a function to check if a number string is pandigital:

const numStr1 = '47458892414';
const numStr2 = '53657687691428890';

const isPandigital = numStr => {
    let legend = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9'];
    for(let i = 0; i 

false
true


How the Algorithm Works

The function works by:


    
Creating an array legend containing all digits '0' to '9'
    
Iterating through each character in the input string
    
If the character exists in legend, removing it from the array
    
Returning true if all digits were found (legend is empty)


Alternative Approach Using Set

Here's a more efficient implementation using JavaScript Set:

const isPandigitalSet = numStr => {
    const digits = new Set(numStr);
    return digits.size === 10 && digits.has('0') && digits.has('1') && 
           digits.has('2') && digits.has('3') && digits.has('4') && 
           digits.has('5') && digits.has('6') && digits.has('7') && 
           digits.has('8') && digits.has('9');
};

// Test with same examples
console.log(isPandigitalSet('47458892414'));
console.log(isPandigitalSet('53657687691428890'));
console.log(isPandigitalSet('1234567890'));


false
true
true


Comparison of Methods

Conclusion

Both methods effectively check for pandigital numbers, but the Set approach is more efficient with O(n) time complexity. Choose the array method for learning purposes and the Set method for production code.