We know that natural numbers in Mathematics are the numbers starting from 1 and spanning infinitely.
First 15 natural numbers are −
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Therefore, the first natural digit is 1, second is 2, third is 3 and so on. But when we exceed 9, then tenth natural digit is the first digit of 10 i.e., 1 and 11th natural digit is the next i.e., 0.
We are required to write a JavaScript function that takes in a number, say n, and finds and returns the nth natural digit.
Example
const findNthDigit = (num = 1) => {
let start = 1;
let len = 1;
let count = 9;
while(num > len * count) {
num -= len * count;
len++; count *= 10;
start *= 10;
};
start += Math.floor((num-1)/len);
let s = String(start);
return Number(s[(num-1) % len]);
};
console.log(findNthDigit(5));
console.log(findNthDigit(15));
console.log(findNthDigit(11));
console.log(findNthDigit(67));Output
And the output in the console will be −
5 2 0 8