I'm using: .js/index.html to mask inputs.

I'm looking at "patterns" option and am having trouble writing the regex expression for 1 or 2 digits with an optional decimal place.

Good inputs:
2.5
12.5
.5
1

Bad inputs:
.25
123.5
1.55

Thank you for any help!

I'm using: http://firstopinion.github.io/formatter.js/index.html to mask inputs.

I'm looking at "patterns" option and am having trouble writing the regex expression for 1 or 2 digits with an optional decimal place.

Good inputs:
2.5
12.5
.5
1

Bad inputs:
.25
123.5
1.55

Thank you for any help!

• javascript
• jquery
• regex
• formatter

1 Answer 1

^\d{0,2}(?:\.\d)?$

• \d{0,2} = 0-2 digits
• \.\d = decimal point followed by 1 digit
• (?: ... )? = optional group
• ^ and $ anchor it to beginning and end

DEMO