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Jacobb Michael20-Oct-09 0:42

20-Oct-09 0:42

Hi,

if it is just one matching you can go with approach 'B'

otherwise i will prefer the First Approach 'A'

because the Second Type has to be parsed as first and process.

and Even if it is more than 2 matching it is not good practice to use 'B'

because it is not much readable and understandable.and for each case we can

make a comment(purpose) in 'A', But it is not suitable for 'B'

but anyway it depends on the place where use, and the situation where you use,and even the appearance where you use

thanks

Pete O'Hanlon20-Oct-09 0:42

Pete O'Hanlon

20-Oct-09 0:42

It depends on the complexity of the case. I'd definitely avoid the second condition because debugging nested ternary's is an absolute nightmare. In a more complex case than this though, I'd drop both constructs in favour of an Action or Func. Have a look at the Log class in my article here[^] to see how it works.

The basic approach is to set up a set of Actions (or Funcs) that correspond to the operations in your switch statement and assign them to a dictionary (the key in the dictionary is the value for your switch statement). All you need do then is trigger the appropriate action based on the key. In the log sample, this line actually performs the validation:

_actions[level](message);

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Thank you all - Switch it is.

nagendrathecoder20-Oct-09 0:50

nagendrathecoder

20-Oct-09 0:50

I'll go for Switch because its easy to track errors in that.

mgkr20-Oct-09 1:06

mgkr

20-Oct-09 1:06

@OriginalGriff
Fixed the switch for ya Poke tongue | ;-P

clarity and readability are much more important than saving space on screen.
Agreed 100%

Which is why I posted - As the ?: was/is very clear to me, and I can at a glance understand what's going on, but I'm well aware it's not a construct used that/as often, so wanted to test the waters with other coders.

-debugging nested ternary's is an absolute nightmare
-I'll go for Switch because its easy to track errors in that.
Good point
As this is a *very* simple case I didn't even think of that actually.
But it might need to get more complicated as the code evolves.
Where I'm using it, it's not very likely though - But those are "famous last words", so point taken and agreed to.

--

Thank you all for the feed back - I'll tidy up my code now Cool | :cool:

N a v a n e e t h20-Oct-09 1:06

N a v a n e e t h

20-Oct-09 1:06

As others said switch is more readable in this case. Also when switch has more labels, compilers use a lookup table (probably hash tables) to implement that and it will yield in accessing all the labels in constant time.

Smile | :)

Best wishes,
Navaneeth

Keith Barrow20-Oct-09 1:10

Keith Barrow

20-Oct-09 1:10

The swtich statement is more readable here, but I think in general swtiches give of a bad code smell:clickety[^]
Especially if they are large or used repeatedly.

CCC solved so far: 2 (including a Hard One!)

PIEBALDconsult20-Oct-09 6:07

20-Oct-09 6:07

In my opinion, a switch on a string value is definitely a code smell. But using if/else or the ternary operator simply to avoid a switch is worse.

Nisha Agrawal20-Oct-09 1:14

Nisha Agrawal

20-Oct-09 1:14

It's not the matter of readability, infact i'll use switch due to performance gain over multiple if-else statements. There is detailed description of this thought here. http://www.ozcandegirmenci.com/post/2008/05/Switch-vs-If.aspx[^]

PIEBALDconsult20-Oct-09 6:04

20-Oct-09 6:04

No, it's definitely about readability.

Luc Pattyn20-Oct-09 1:53

Luc Pattyn

20-Oct-09 1:53

mgkr wrote:
What would you use (and why)?

neither, because
1) needing such a conversion often indicates a bad design e.g. a bad choice of data structuring;
2) and when unavoidable, i.e. when I do need to map characters to small positive integers, I use a snippet that is based on "literalString".IndexOf(char)

PS: at least two replies mentioned readability, which does not even appear (any more?) in the OP.
I hate it when the OP gets edited, and yes readability is very important.

Smile | :)

Luc Pattyn

I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages

Local announcement (Antwerp region): Lange Wapper? 59.24% waren verstandig genoeg om NEEN te stemmen; bye bye viaduct.

PIEBALDconsult20-Oct-09 5:49

20-Oct-09 5:49

10!

PIEBALDconsult20-Oct-09 5:56

How to lock the column width expansion in list view at run time

20-Oct-09 5:56

Neither.

public enum IDenum { None , a , b , c }

...

IDenum ID = System.Enum.Parse ( typeof(IDenum) , whatever ) ;

(Except I use my own TryParse method.)

@nisha 2n19-Oct-09 23:21

@nisha 2n

19-Oct-09 23:21

How to lock the column width expansion in list view at run time

anu gunturi

Re: How to lock the column width expansion in list view at run time

Jacobb Michael20-Oct-09 1:48

Re: How to lock the column width expansion in list view at run time

20-Oct-09 1:48

Hi

Just a simple approach, but not feasible,

see bellow code

private void listView1_ColumnWidthChanged(object sender, ColumnWidthChangedEventArgs e)
        {
            if(listView1.Columns[e.ColumnIndex].Width != 50)
                listView1.Columns[e.ColumnIndex].Width = 50;
        }

check the static column width, if it miss matches then it is changed so reset it , this is a simple approach, if you find some other good method follow that.

thanks

SimpleData20-Oct-09 5:57

SimpleData

20-Oct-09 5:57

Actually this would a little be better:

private void listView1_ColumnWidthChanged(object sender, ColumnWidthChangedEventArgs e)
{
 e.Cancel = true;
 e.NewWidth = listView1.Columns[e.ColumnIndex].Width;
}

Regular Expression ?

Jacobb Michael19-Oct-09 23:07

19-Oct-09 23:07

Hi all

Can some one lead me for a good logic to generate the regular expression dynamically.

Example:

I give an input like bellow

1. Us phone no - (910)456-8970 => regular expression is: @"$\d{3}$\s\d{3}-\d{4}"

2. Email Id - miltoncse00@yahoo.com => string pattern=@"^[a-z][a-z|0-9|]*([_][a-z|0-9]+)*([.][a-z|" +
@"0-9]+([_][a-z|0-9]+)*)?@[a-z][a-z|0-9|]*\.([a-z]" +
@"[a-z|0-9]*(\.[a-z][a-z|0-9]*)?)$";

My Need,

By getting (910)456-8970 this string i want to construct the regular expression like @"$\d{3}$\s\d{3}-\d{4}"

and i have to do for all the string vice versa. Can some tell me some techniques or logic to incorporate.

My Real Problem With Regular Expression :

I have to mask the fields in website based on the pattern like usphone,emailid etc...

thanks in Adavance

Eddy Vluggen20-Oct-09 1:29

Eddy Vluggen

20-Oct-09 1:29

I doubt that you can (correctly) deduce a regex from sample data. Take the phone-number column as an example, with this data;

555-423325

What mask would the first three five's generate, and would that mask be reusable as a phone-number-mask?

It gets worse, since the generated mask isn't a phone-number-mask (even if you base it on the data in that column) - it will be a mask that allows all data within that column (since that's what it's based on).

The best approach would be to make a list of examples for each column, containing correct and incorrect values. Next, you base the regex on the domain of the values that you expect. Lastly, a unit-test to verify that the regex works Smile | :)

I are Troll Smile | :)

Jacobb Michael20-Oct-09 1:58

20-Oct-09 1:58

Hi thanks for your reply,

The mask is not only for a corporate sites, it is for the entire web.

if i specify to mask all the security No (SSN) in a page, even if i Google it also, i have to mask the SSN in the Google page as (XXXXXXXX). I have done that using ihtmlElementCollection (BHO). My problem is i know SSN format so there is no issue.But there can be any format, so just seeing one format dynamically i want to generate the regex. This question may be quiet meaningless, but we can could arrive a solution. if no one had come across like this, then i will try to generate a algorithm to achieve, but my thinking is, if already some one knows on that, then i don't want to wast my time to creating algorithm again.

thanks any suggestions are greatfull

Thanks

Eddy Vluggen20-Oct-09 2:02

Eddy Vluggen

20-Oct-09 2:02

jasome wrote:
But there can be any format, so just seeing one format dynamically i want to generate the regex.

Your application encounters the string "8572398947". Is that my SSN (being Dutch), or my SSN + 1, or just a random number? How would you know that the string is in fact, a SSN if you cannot verify that it is?

I are Troll Smile | :)

Jacobb Michael20-Oct-09 2:13

20-Oct-09 2:13

Hi,

Good exactly you are correct,

sorry for taking the SSN no instead take USPHone No like ... etc..

added to that for SSN there is option to mask based on the Field value, for

example if the input/span element contain SSN then i mask that.

This regex is only for unique analyzing

for example if i give :
user@gmail.com - we can make regular expression for all the mails,

Thanks for your continuous encouragement

you are most welcome to make a comment on that....

J4amieC20-Oct-09 2:38

J4amieC

20-Oct-09 2:38

jasome wrote:
for example if i give :
user@gmail.com - we can make regular expression for all the mails,

So taking this example, you take that input and generate an "email address" regex from it. Now I try to enter my email address (which is .co.uk) and whoops, it fails. Yet mine is a totally valid email address.

There is absolutely no way you can make a regular expression from input data and have it work in all cases.