checking if key exists in dictionary

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C#

How do you check to see if a key exists in a Dictionary?

Posted 17-Aug-11 16:11pm

shekarchee

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4 solutions

Solution 1

Have you searched in google[^]?

Posted 17-Aug-11 16:17pm

Firo Atrum Ventus

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Anthony Mushrow · Accepted Answer · 2011-08-17T16:19:00

Solution 2

You can tell if a dictionary has a key in it because it won't close properly, unless it's a really small key.

Honestly, you spent more time typing that message than it would have taken to just look yourself. Documentation[^] It's not just there for fun.

Posted 17-Aug-11 16:19pm

Anthony Mushrow

Comments

Sergey Alexandrovich Kryukov 17-Aug-11 23:03pm

Exactly. Also, it could be hard to tell if the dictionary is really big. My 5.
--SA

Wonde Tadesse · Accepted Answer · 2011-08-17T16:55:00

Solution 4

Just use ContainsKey Method[^] to check a key existence in the dictionary.

Posted 17-Aug-11 16:55pm

Wonde Tadesse

Comments

Sergey Alexandrovich Kryukov 17-Aug-11 23:08pm

Sure, a 5. I credited your answer in mine -- another way is TryGetValue, please see my answer.
--SA

Wonde Tadesse 6-Dec-11 11:18am

Thanks

Sergey Alexandrovich Kryukov · Accepted Answer · 2011-08-17T17:07:00

Solution 5

In addition to what Wonde advised: you can also use System.Collections.Generic.Dictionary.TryGetValue, see http://msdn.microsoft.com/en-us/library/bb347013.aspx[^].

To confirm what SK Genius say, you would spent more time typing that message than it would have taken to just look yourself.

—SA

Posted 17-Aug-11 17:07pm

Sergey Alexandrovich Kryukov

Comments

Wonde Tadesse 17-Aug-11 23:08pm

5+. Another possible solution.

Sergey Alexandrovich Kryukov 17-Aug-11 23:09pm

Thank you, Wonde. How could you be so fast?
--SA

Wonde Tadesse 17-Aug-11 23:23pm

No wonder.I'm fast like lightning.:) Just kidding.As usual I was browsing the Q/A sections and suddenly my reputation points up lifted drastically.Finally I just checked my answers what I replied ... I am here look what I got.

Sergey Alexandrovich Kryukov 17-Aug-11 23:27pm

We're more overwhelmed by tons of bad questions these days, have less time to review each others solutions...
--SA

Wonde Tadesse 17-Aug-11 23:35pm

Very True. These days I am quite busy in office. I am less active than before. But still I am checking some members solution.

Sergey Alexandrovich Kryukov 18-Aug-11 11:54am

Me too... but I'm trying not to disappear completely.
Good to hear from you.
--SA

Wendelius 18-Aug-11 0:43am

Good alternative especially because the actual value is most likely needed later in the code. My 5

Sergey Alexandrovich Kryukov 18-Aug-11 11:53am

Exactly. It depends on where to check up the presence of the key.
Thank you, Mika.
--SA