Regex for positive float numbers

Question

For example:
10
0.1
1.23234
123.123
0.000001
1.000
.3

And wrong examples:
0001.2
-12
-1.01<

Answer 1

Try this here

^(?:[1-9]\d*|0)?(?:\.\d+)?$

See it here online on Regexr

If matching the empty string is not wanted, then you can add a length check to your regex like

^(?=.+)(?:[1-9]\d*|0)?(?:\.\d+)?$

The positive lookahead (?=.+) ensures that there is at least 1 character