Returning a substring with Regex

[Mark Rae]

Hi,

I've been set the task of using Regex to strip off the postcode area from a
UK postcode, i.e. the bit before the first numerical character, as in:

"N11AA" returns "N"

and

"SW1A1AA" returns "SW"

I've been asked *specifically* to use Regex for this - can anyone help?

Thanks,

Mark

[Ignacio Machin \( .NET/ C# MVP \)]

Hi,

Unless you explain how the postal codes work in UK only a english person
can help you :)

Tip: look in google groups for this, you may find an expression, remember
that you can use both javascript & java regex almost without changes.
Cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation

"Mark Rae" <ma**@mark-N-O-S-P-A-M-rae.co.uk> wrote in message
news:%2****************@tk2msftngp13.phx.gbl...

Hi,

I've been set the task of using Regex to strip off the postcode area from a UK postcode, i.e. the bit before the first numerical character, as in:

"N11AA" returns "N"

and

"SW1A1AA" returns "SW"

I've been asked *specifically* to use Regex for this - can anyone help?

Thanks,

Mark

[C Addison Ritchie]

Mark,

I know you said that it has been specified that you use Regular Expressions
but I would argue with whoever gave me this contraint to consider the expense
of Regex.

1. For this type of operation Regex will be a bit slower then just
iteration over the string.
2. Regex is a difficult "language" to master. The code would be harder to
maintain.

With that I give you this.... use it for what it is worth. It should
perfrom better than Regex.

public string GetPostCode(string postalCode)
{
StringBuilder postCode = new StringBuilder();

foreach(char bit in postalCode)
{
if (bit > 'A' && bit < 'Z')
{
postCode.Append(bit);
}
else
{
throw new ApplicationException("Invalid Postal Code");
// or just
break;
}

return postCode.ToString();
}

Good luck convincing the higher ups.

--
C Addison Ritchie, MCSD.NET
Ritch Consulting, Inc.
"Mark Rae" wrote:

Hi,

I've been set the task of using Regex to strip off the postcode area from a
UK postcode, i.e. the bit before the first numerical character, as in:

"N11AA" returns "N"

and

"SW1A1AA" returns "SW"

I've been asked *specifically* to use Regex for this - can anyone help?

Thanks,

Mark