Question

I would like to have a regular expression that can work in a simple calculator:

Right now I have: this.field.value.match(/\./))

My problem is I can only insert one decimal at a time:

eg:
2.5 + 2 OR
3 + 3.55

I would like the ability to have the option of adding 2.5 + 2.5. The point is, I’m trying to prevent someone from typing 2.5.5.5 + 5

Answer 1

Try this

/ *(\d+\.?\d*|\d*\.?\d+) *\+ *(\d+\.?\d*|\d*\.?\d+) */

Matches

1   + 1
1.0 + 1.0
1.  + 1.
0.1 + 0.1
.1  + .1

and so on.

Doesn’t match

.  + .
1  +
.1 +
1. +

and so on…

Also matches whitespace between + sign and on beginning and end of input.