LINQ 101 error

[Mike P]

I am working through the LINQ 101 examples, and have found another
error, for the FirstIndexed example :

int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };

int evenNum = numbers.First(( num, index) =(num % 2 == 0) &&
(index % 2 == 0));

lbl.Text = evenNum + " is an even number at an even position
within the list.";

The error is : Delegate 'System.Func<in t,bool>' does not take '2'
arguments. Does anybody know the correct syntax?

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[Marc Gravell]

Re: LINQ 101 error

I think you now need to use the "int,int,bo ol" predicate first:

int evenNum = numbers.Where(( num, index) =(num % 2 == 0) && (index % 2
== 0)).First();

The First extension method now only has a parameterless overload and a
predicate (Func<T,bool>) overload - not an index-based predicate overload.

Marc

[Chris Dunaway]

Re: LINQ 101 error

On Aug 22, 8:32 am, Mike P <mike.p...@gmai l.comwrote:

I am working through the LINQ 101 examples, and have found another
error, for the FirstIndexed example :
>
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
>
int evenNum = numbers.First(( num, index) =(num % 2 == 0) &&
(index % 2 == 0));
>
lbl.Text = evenNum + " is an even number at an even position
within the list.";
>
The error is : Delegate 'System.Func<in t,bool>' does not take '2'
arguments. Does anybody know the correct syntax?
>
*** Sent via Developersdexht tp://www.developersd ex.com***

The First extension method only takes a delegate that has a single
integer parameter and returns bool. You are passing a delegate that
take 2 integer arguments and returns bool. They must have a mistake
in the example. Perhaps this will be closer to what they intended:

int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
var evenNum = numbers.Select( (num, index) =(num % 2 ==
0) && (index % 2 == 0));

Chris