some problem with defination...c#

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Hi, I need some one to explain me some code in c#, what does they mean... I am using that but to tell te truth I don understand that
here is the code :

C#

GroupBy(name => name).Select(group => string.Format("{0} [{1}]",group.Key , group.Count()))

string.Format("{0} [{1}]  --- ???  I have the result  e.x  Europe[4]

so can explain any one, what does it mean "{0} ande [{1}] " thank you

gorup.key ---?
group.Count----?

Posted 26-May-12 1:24am

h5h5

Updated 26-May-12 1:33am

P.Salini

v3

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Comments

Philippe Mori 26-May-12 13:25pm

I think you can at least read the help on a function before asking trivial questions.

3 solutions

Solution 2

Can You Specify what is GroupBy whether it is DataTable or Dictionary or some thing else

As for the string format it will concatenate the string what ever you give as a parameter.Those brackets are just the position in what popsition what text should come so 0'th position group.key value will come and at {1} object count will come

Posted 26-May-12 1:47am

bopannavb

Solution 3

To understand LINQ I would look at the following article: How does it work in C#? - Part 3 (C# Linq in detail)[^]

Posted 26-May-12 19:31pm

Clifford Nelson

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OriginalGriff · Accepted Answer · 2012-05-26T01:42:00

{0} and {1} are parameters to the string.Format format string, which are replaced by the first and second parameters following the format string when constructing a new string: in this case, by "group.Key" and "group.Count()" respectively. The '[' and ']' characters are just literal characters copied directly to the output string - as you can see in your print. There are 4 "Europe" items.

"group" is the name given to each item in the enumerable list returned by the GroupBy Linq extension method.
Think of it as:

C#

foreach (var group in GroupBy(name => name))
   {
   Select(string.Format("{0} [{1}]",group.Key , group.Count()));
   }

It isn't done like that, and that wouldn't compile anyway, but it gives you an idea what is going on.