Validate negative and positive decimal numbers with RegEx

Question

I am trying to build a regex which will allow both negative and positive decimal numbers with the following rules.

1. there can not be more than 2 digits after de

Answer 1

It is pretty straightforward since 12 - 9 == 3 for two decimals + the dot.

var re = new RegExp('^-?\\d{1,9}(\\.\\d{1,2})?$');

authorizes

• -123456789
• -123456789.1
• -123456789.12
• 0
• 0.12

but will not accept

• 01234567890123 more than 12 decs
• 123. a dot without decimals
• 123.123 more than two decimals
• . or .12 (missing 0)

Answer 2

My own regex:

var rgx = /^(-{1}?(?:([0-9]{0,10}))|([0-9]{1})?(?:([0-9]{0,9})))?(?:\.([0-9]{0,3}))?$/;

Answer 3

var NumberToValidate = 48428;
        var valid =  /^([0-9]*[1-9][0-9]*)$/.test(NumberToValidate);
        {
        if (!valid)
    alert("Invalid Quantity!!\nThe Quantity cannot be Zero\n or a part of a Unit !");
            return false;
        }

Answer 4

Check this regex.

^[+-]?[0-9]{1,9}(?:\.[0-9]{1,2})?$

This regex says

• sign is optional
• at least one and max 9 digits as integer part
• if decimal point is there, at least one and max two digits after it.

Answer 5

/(?:^(?:(?:[1-9][0-9]{1,})|0)\.[0-9]{1,}$)|^[1-9]+[0-9]*$/