Date: 2007oct11
Update: 2025aug5
Language: javaScript
Q. javaScript: javaScript has no sprintf() ... how can I zero pad a number?
A. Use this function:
// n = number you want padded
// digits = length you want the final output
function zeroPad(n, digits) {
n = n.toString(); // In case an unquoted number is passed in
while (n.length < digits) {
n = '0' + n;
}
return n;
}
function exampleUse() {
// Pad 123 to 8 digits
const a = zeroPad(123, 8);
alert('a=' + a);
}
I like this function because its very clear.
As a bonus, a naive Java version
static String zeroPad(String n, final int digits) {
while (n.length() < digits) {
n = '0' + n;
}
return n;
}