Regular Expressions

Hi, I need to create a regular expression in Java to accept floating point numbers.
These are the requirements that I have been given:

A floating point number consists of:

• an optional sign ('+' or '- ')
• an integer part (a sequence of digits)
• an optional fractional part (a decimal point `.' followed by a sequence of digits)
• an optional exponent part, consisting of
  • an exponent indicator (`e' or `E')
  • an optional sign (`+' or '-')
  • a non-empty sequence of digits

At least one of the digit sequences ``integer part'' or ``fractional part'' must be non-empty. The floating point number may not contain any spaces.

For example, all of the following are valid floating point numbers:

• 56
• 3.14159
• -1e6
• .5
• 1.0E-6

The following are not valid floating point numbers:

• 12E (empty exponent part)
• e6 (empty integer and fractional part)
• .e6 (empty integer and fractional part)
• -+7 (two signs)
• 23.-56 (sign in fractional part)
• 2.13 E 25 (contains spaces)

Any replies much appreciated.
Thanks.

Hey Paul83!

Here's your regExp: ^[+|-]?[0-9]+(\.[0-9]+)?([eE][+|-]?[0-9]+)?$

This validates your examples. Although, you wrote an example that is not valid:




Anyway...hope this meets your requirements!

Good Luck!

ANibal.

Hi everyone,

I have been asked to validate using REGEXP the following scenario:

V-123.456.789

Where:
1.- Either "V-" or "E-" always have to be at the beginning,
2.- The digits are an integer representation of a number from 1 to 999999999, using the "." as a 3 digits separator (if necessary as thousands representation).
3.- The digits cannot have leading zeros (0)

So, some valid entries could be:
V-1
E-1.234
V-12.345
V-1.234.567
V-123.456.789
V-123.012.345

Some invalid entries would be:
V-012.345.678
V-123456789
F-123.
E-1234.123

I have tried using the fol owing REGEXP but I don't think to be right:
^([VE]{1}\-)[0-9]+(.\d{3})* )?&

Any ideas...

Thanks

Sorry, I made some typos. This is the one I have built so far:

^([VE]{1}\-)\d+(\.\d{3})*&

No spaces allowed either. Anyway, it doesn't seem to work.

Looking forward for any ideas...

Thanks

This is closer to what I need, but still doesn't validate when no "." are used every three digits for thousands separation:

^[VE]{1}\-{1}[^0]{1}[0-9]+(\.[0-9]{3})*$

Still looking for your ideas...

Regards