Regular expressions and numerical only input

[Trev]

Hi everyone,

I'm having some problems with my regular expressions in C# and was
wondering if anyone could help?

Basically, what I'm trying to do is check for numerical only input -
either integer, or double,
so I need to check for 1234, 1234.5 etc.

The integer check I think is as follows:
Match m = Regex.Match( MyString, "^[0-9]*$");

but I'm having problems checking for anything with a decimal point in
it
Match m = Regex.Match( MyString, "^[0-9]*/\.{0,1}/[0-9]*$");

- the compiler grumbles about unknown tokens and syntax errors.

TIA

Paul

[SirMike]

Dnia 16 Nov 2006 03:42:43 -0800, Trev napisa³(a):

Match m = Regex.Match( MyString, "^[0-9]*/\.{0,1}/[0-9]*$");

try
Match m = Regex.Match( MyString, @"^[0-9]*/\.{0,1}/[0-9]*$");

--
SirMike - http://www.sirmike.org

C makes it easy to shoot yourself in the foot; C++ makes it harder, but
when you do, it blows away your whole leg. - Bjarne Stroustrup

[Hans Kesting]

Hi everyone,

>
I'm having some problems with my regular expressions in C# and was
wondering if anyone could help?

Basically, what I'm trying to do is check for numerical only input -
either integer, or double,
so I need to check for 1234, 1234.5 etc.

The integer check I think is as follows:
Match m = Regex.Match( MyString, "^[0-9]*$");

but I'm having problems checking for anything with a decimal point in
it
Match m = Regex.Match( MyString, "^[0-9]*/\.{0,1}/[0-9]*$");

- the compiler grumbles about unknown tokens and syntax errors.

TIA

Paul

the "\" is special within strings for the C# compiler, unless escaped.
Use:

Match m = Regex.Match( MyString, "^[0-9]+(\\.[0-9]+)?$");
or
Match m = Regex.Match( MyString, @"^[0-9]+(\.[0-9]+)?$");

this will match:
123
123.5
0.3

and not match
123.
..6

Hans Kesting

[Michael Nemtsev]

I'd recommed to find the appropriate match there
http://regexlib.com/default.aspx

--
WBR,
Michael Nemtsev :: blog: http://spaces.live.com/laflour

"At times one remains faithful to a cause only because its opponents do not
cease to be insipid." (c) Friedrich Nietzsche


"Trev" wrote:

Hi everyone,

I'm having some problems with my regular expressions in C# and was
wondering if anyone could help?

Basically, what I'm trying to do is check for numerical only input -
either integer, or double,
so I need to check for 1234, 1234.5 etc.

The integer check I think is as follows:
Match m = Regex.Match( MyString, "^[0-9]*$");

but I'm having problems checking for anything with a decimal point in
it
Match m = Regex.Match( MyString, "^[0-9]*/\.{0,1}/[0-9]*$");

- the compiler grumbles about unknown tokens and syntax errors.

TIA

Paul

[Trev]

Thanks - works beautifully!

Cheers

Trev

[Trev]

If I wanted to check for only integers, would this work? I've put
\.{0}, which I think means
"match the decimal point zero times exactly"

m = Regex.Match( args[0].ToString(), @"^[0-9]+(\.{0}[0-9]+)?$");

[Rad [Visual C# MVP]]

Hey Trev,

Here are a couple of regexes to help you out

^\d+$

This one will match any whole number with no decimals

So it will match,1, 5, 100, 600.

^\d+(?:\.\d+)*$

This one will match any whole number as well as any number with
decimals

So it will match 1, 5, 100, 600, 5.5, 80.3 and 3.151512924

On 17 Nov 2006 03:49:11 -0800, "Trev" <t.*********@btinternet.com>
wrote:

>If I wanted to check for only integers, would this work? I've put
\.{0}, which I think means
"match the decimal point zero times exactly"

m = Regex.Match( args[0].ToString(), @"^[0-9]+(\.{0}[0-9]+)?$");

--

Bits.Bytes.
http://bytes.thinkersroom.com

[Trev]

Thanks mate, got that sorted out, cheers, no probs!

Still having some other regex woes though. If I wanted to check for "a
is b and c is d"
where a and c can be X,Y,Z and b and d can be N,S,E,W,D,U (eg "Y is N
and Z is U")
what expression should I use?

m = Regex.Match( args[0].ToString(),
@"(/X|Y/Z/)(\s)(/is/)\2(/N|E|W|S|D|U/)\2(/and/)\1\2\3\2\4");

doesn't work :(
bummer.

[Trev]

Trev wrote:

Thanks mate, got that sorted out, cheers, no probs!

Still having some other regex woes though. If I wanted to check for "a
is b and c is d"
where a and c can be X,Y,Z and b and d can be N,S,E,W,D,U (eg "Y is N
and Z is U")
what expression should I use?

m = Regex.Match( args[0].ToString(),
@"(/X|Y/Z/)(\s)(/is/)\2(/N|E|W|S|D|U/)\2(/and/)\1\2\3\2\4");

doesn't work :(
bummer.

Spotted a mistake. It should be
m = Regex.Match( args[0].ToString(),
@"(/X|Y|Z/)(\s)(/is/)\2(/N|E|W|S|D|U/)\2(/and/)\1\2\3\2\4");

- but it still doesn't want to play :(

[Rad [Visual C# MVP]]

Hey Trev,

Try this one

[X-Z]{1} is [NSEWDU]{1} and [X-Z]{1} is [NSEWDU]{1}

It matches these ones

X is N and X is W
Y is S and Y is D
Z is E and Z is U

On 20 Nov 2006 01:44:23 -0800, "Trev" <t.*********@btinternet.com>
wrote:

>
Trev wrote:

>Thanks mate, got that sorted out, cheers, no probs!

Still having some other regex woes though. If I wanted to check for "a
is b and c is d"
where a and c can be X,Y,Z and b and d can be N,S,E,W,D,U (eg "Y is N
and Z is U")
what expression should I use?

m = Regex.Match( args[0].ToString(),
@"(/X|Y/Z/)(\s)(/is/)\2(/N|E|W|S|D|U/)\2(/and/)\1\2\3\2\4");

doesn't work :(
bummer.

Spotted a mistake. It should be
m = Regex.Match( args[0].ToString(),
@"(/X|Y|Z/)(\s)(/is/)\2(/N|E|W|S|D|U/)\2(/and/)\1\2\3\2\4");

- but it still doesn't want to play :(

--

Bits.Bytes.
http://bytes.thinkersroom.com