java - Regex for decimal or fraction

Question

Right now I have a regex where it checks if the string in a decimal format or not:

-?\d+(?:.\d+)//any positive or negative number, including decimals

If I wanted to create a regex for a fraction, which may also consist of decimals, such as:

• 3.1/2.6
• 1.00/5.00

Would the following be valid?

 -?\(d+(?:.\d+)|d+(?:.\d+)/d+(?:.\d+))//a decimal OR a fraction(including decimals)

Answer 1

You can use this regex to support positive/negative integers, decimals with optional fractional part:

-?\b\d+(?:\.\d+)?(?:/\d+(?:\.\d+)?)?\b

RegEx Demo

Or if you're using Java's String#matches() method then use this regex:

-?\d+(?:\.\d+)?(?:/\d+(?:\.\d+)?)?