Regex Matching numbers with floating point

Question

I have this pattern:

[0-9]*\\.?[0-9]

It matches numbers but it also matches 3.5.4 as:

1. 3.5
2. .4

How to f

Answer 1

To match a json number:

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

Use this regex to match .123:

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