regex to strip leading zeros treated as string

Question

I have numbers like this that need leading zero\'s removed.

Here is what I need:

00000004334300343 -> 4334300343

000

Answer 1

The correct regex to strip leading zeros is

str = str.replaceAll("^0+", "");

This regex will match 0 character in quantity of one and more at the string beginning. There is not reason to worry about replaceAll method, as regex has ^ (begin input) special character that assure the replacement will be invoked only once.

Ultimately you can use Java build-in feature to do the same:

String str = "00000004334300343";
long number = Long.parseLong(str);
// outputs 4334300343

The leading zeros will be stripped for you automatically.