I want to implement a function to check if a given number do contain les than two different digits, that are called duodigits
For example :
12 , 110 , -33333 : are all duodigits , since they have no more than two different digits 102 : is not a duodigit since his digits ; 1 and 0 and 2 are three different digits
How may I implement a method , which may iterate and check if it's a duodgits or not and return true or false as result
Here is how I would do it:
/**
* Checks if a number is a duodigit.
* @param {number} num
* @returns {boolean}
*/
function isDuodigit(num) {
return new Set(Math.abs(num).toString()).size <= 2;
}
my solution would be:
function isDuoDigit(num) {
const numArr = Array.from(num.toString());
const uniqueNums = numArr.filter((num, index) => numArr.indexOf(num) === index);
return uniqueNums.length > 2 ? "Number is not DuoDigit" : "Number is DuoDigit!"
}
console.log(isDuoDigit(11111000000)); // Number is DuoDigit!
console.log(isDuoDigit(111155555500000)); // Number is NOT DuoDigit!Convert a number to an array of strings ( 102 = ["1", "0", "2"] )
const numArr = Array.from(num.toString());
Get an array with unique values (without duplicates)
const uniqueNums = numArr.filter((num, index) => numArr.indexOf(num) === index);
We check if length of uniqueNums array is more then 2. If it's true, it means number is NOT DuoDigit and if length of array 2 or less, number is DuoDigit
return uniqueNums.length > 2 ? "Number is not DuoDigit" : "Number is DuoDigit!"
If you want to do it without a set or string conversion.
function isDuoDigit(num){
num = Math.abs(num);
let first = '', second = '';
while (num > 0) {
let digit = num % 10;
if(first === '')
first = digit
else if(second === '')
second = digit
else if(first !== digit && second !== digit)
return false;
num = Math.trunc(num / 10);
}
return true;
}