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GeneralRe: Error: Object reference not set to an instance of an object in C# Pin
Pete O'Hanlon17-Jan-18 5:41
subeditorPete O'Hanlon17-Jan-18 5:41 
GeneralRe: Error: Object reference not set to an instance of an object in C# Pin
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QuestionException raised at wpf designer level Pin
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QuestionHow to convert a query to lambda based Pin
Mou_kol16-Jan-18 2:43
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AnswerRe: How to convert a query to lambda based Pin
OriginalGriff16-Jan-18 2:52
mvaOriginalGriff16-Jan-18 2:52 
GeneralRe: How to convert a query to lambda based Pin
Mou_kol16-Jan-18 4:50
Mou_kol16-Jan-18 4:50 
GeneralRe: How to convert a query to lambda based Pin
Mou_kol24-Jan-18 1:26
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GeneralRe: How to convert a query to lambda based Pin
OriginalGriff24-Jan-18 1:44
mvaOriginalGriff24-Jan-18 1:44 
Linq queries and Linq methods aren't executed immediately, they use something called "Deferred execution" which (basically) means that nothing is done until you actually need the final results.
There is a basic example of this here: Deferred Execution Example (C#) | Microsoft Docs[^]

Deferred execution means better efficiency (sometimes) because you can "combine operations" instead of having to loop each time to produce the intermediate result which you then pass to the next section of the evaluation. Remember: Linq isn't "no loops" it's about "hiding loops" where you can't see them and evaluating them only when it has to.

But ... when you say "ToList" you are explicitly requesting an object be created holding the whole results - so the whole operation has to be performed immediately to generate the collection you asked for. So when you then continue to process it, you need to do another loop to process the next operation.
Every time you call ToList, you make Linq work harder, and that takes both more time, and uses more memory. Only ever "Collapse the operation" when you actually need the results!
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AnswerRe: How to convert a query to lambda based Pin
Richard Deeming16-Jan-18 4:03
mveRichard Deeming16-Jan-18 4:03 
GeneralRe: How to convert a query to lambda based Pin
Mou_kol16-Jan-18 4:50
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GeneralRe: How to convert a query to lambda based Pin
Mou_kol24-Jan-18 1:35
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Questioncontour plot in visual studio Pin
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AnswerRe: contour plot in visual studio Pin
Richard MacCutchan15-Jan-18 8:15
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QuestionI got the error that: Not all code paths return a value Pin
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AnswerRe: I got the error that: Not all code paths return a value Pin
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AnswerRe: I got the error that: Not all code paths return a value Pin
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QuestionSpeech recognition: Unable to LoadGrammar and no installed recognizer Pin
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QuestionSelect data from MSSQL database and insert into oracle database Pin
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AnswerRe: Select data from MSSQL database and insert into oracle database Pin
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AnswerRe: Select data from MSSQL database and insert into oracle database Pin
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GeneralRe: Select data from MSSQL database and insert into oracle database Pin
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GeneralRe: Select data from MSSQL database and insert into oracle database Pin
Richard Deeming12-Jan-18 4:45
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GeneralRe: Select data from MSSQL database and insert into oracle database Pin
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QuestionSystem.IO.IOException: 'The I/O operation has been aborted because of either a thread exit or an application request Pin
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AnswerRe: System.IO.IOException: 'The I/O operation has been aborted because of either a thread exit or an application request Pin
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