I have a line of code using where:
codebase.Methods.Where(x => x.Body.Scopes.Count > 5);
How can I insert more than one condition? So I can say x => predicate && y => predicate?
Thanks
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7 Answers
You can roll your separate conditions into a single predicate if you like:
codebase.Methods.Where(x => (x.Body.Scopes.Count > 5) && (x.Foo == "test"));
Or you can use a separate Where call for each condition:
codebase.Methods.Where(x => x.Body.Scopes.Count > 5)
.Where(x => x.Foo == "test");
3 Comments
dwbrito
Considering big clauses with much information, do both cases have the same complexity or is the first one slower?
LukeH
@alaxid: I would expect the second one to be slightly slower, because each
Where call incurs a small extra overhead (method call, delegate invocation etc). I wouldn't be worried about this in any normal day-to-day scenarios though.
Dalibor
What about OR clause? Multiplying .Where would act as AND
no you can't define 2 delegates in the same where but you can build after each other or put both on same condition like this
var result = codebase.Methods.Where(x => x.Body.Scopes.Count > 5 && x.Body.Scopes.name == "" );
or
var result = codebase.Methods.Where(x => x.Body.Scopes.Count > 5 )
.where( y=> y.Body.Scopes.name == '' );
or
var result = codebase.Methods.Where(x => x.Body.Scopes.Count > 5 )
.Union( codebase.Methods.Where(y => y.Body.Scopes.name == '' ) );
Comments
In your example, where does y come from? The Where method takes a lambda with a single input parameter, which represents a single instance of the sequence you're operating against.
You can, of course, have multiple conditions against x:
Where(x => x.Foo > 5 && x.Bar < 3)
Comments
What would "y" represent?
You can just use a standard && condition. No need for a "y":
codebase.Methods.Where(x => x.Body.Scopes.Count > 5 && x.Body.SomethingElse < 14);
answered Feb 17, 2010 at 13:47
TheSoftwareJedi
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Comments
I don't get it. What can you not do?
codebase.Methods.Where(x => x.Head.IsHairy && x.Body != null && x.Body.Scopes.Count > 5);
answered Feb 17, 2010 at 13:48
Klaus Byskov Pedersen
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1 Comment
Joseph Morgan
The y that is mystifying you is just sort of a stand-in for the <YourType> object to be tested against in the filter. It may be called an "Anonymous Delegate" but I am not sure. In any case, it just provides a variable for you to use to access the properties of your type in the lambda expression. You could use any legal variable name.
like this..
codebase.Methods.Where(x => x.Body.Scopes.Count > 5 && x.Body.Scopes.Count < 10);
Comments
codebase.Methods.Where(x => x.Body.Scopes.Count > 5).Where(x => x.Body.Scopes.TypeName == "Scopes").Where(x => x.Body.Scopes.Level == LEVEL_HIGH);
