src code

instance method Number#toPaddedString 

Number#toPaddedString(length[, radix]) → String
  • length (Number) – The minimum length for the resulting string.
  • radix (Number) – An optional radix for the string representation, defaults to 10 (decimal).

Returns a string representation of the number padded with leading 0s so that the string's length is at least equal to length. Takes an optional radix argument which specifies the base to use for conversion.

Examples
(13).toPaddedString(4);
// -> "0013"
 (13).toPaddedString(2);
// -> "13"
 (13).toPaddedString(1);
// -> "13"
 (13).toPaddedString(4, 16)
// -> "000d"
 (13).toPaddedString(4, 2);
// -> "1101"