Checking for the Gapful numbers in JavaScript

A number is a gapful number when −

• It has at least three digits, and

• It is exactly divisible by the number formed by putting its first and last digits together

For example:

1053 is a gapful number because it has 4 digits and it is exactly divisible by 13.
135 is a gapful number because it has 3 digits and it is exactly divisible by 15.

Our job is to write a program that returns the nearest gapful number to the number we provide as input.

Let’s write the code −

const n = 134;
//receives a number string and returns a boolean
const isGapful = (numStr) => {
   const int = parseInt(numStr);
   return int % parseInt(numStr[0] + numStr[numStr.length - 1]) === 0;
};
//main function -- receives a number, returns a number
const nearestGapful = (num) => {
   if(typeof num !== 'number'){
      return -1;
   }
   if(num 
The output in the console will be −
135