How to use Regex to limit user input to numeric fields, with one allowed decimal and one allowed neg-CodePudding

I am trying to only allow numeric values, along with a possible negative symbol at the front of the string, and a single decimal, using Regex in JavaScript. This input value will only allow for a possible 10 digits also.

Currently, when a user inputs text, I have this logic that will only allow numbers, negative signs, and decimals. However, I want to limit the number of the negative sign to one, and only allow this at the front of the string. Also, I want to limit the number of decimals to one.

input.slice(0, 10).replace(/[^0-9.\-]/, '');

Can anyone please help me figure this out?

CodePudding user response：

You can do:

input.slice(0, 10).match(/([-]?)([0-9] )([.]?)([0-9]?)/);

CodePudding user response：

Short n sweet.

/^-?\d{0,10}(\.\d{0,3})?$/

optional negative char. at the start
allows max of 10 digits next
again optional decimal group with at most 3 decimal places

These barriers can be modified accordingly.