24 LINQ questions from the C# bank, written for Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd.
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A.the performance and correctness hazard of iterating a lazily-evaluated query more than once, re-executing the underlying work or yielding inconsistent results, often avoided by materializing to a list or array
B.the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
C.the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
D.a category of operators such as ToList, ToArray, Count, and First that force the query to evaluate at once rather than lazily
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2. Which term means: "the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration"?
Mid
A.Deferred execution
B.Multiple enumeration pitfall
C.Query syntax
D.Method syntax
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3. Which statement is correct?
Mid
A.Deferred execution — the performance and correctness hazard of iterating a lazily-evaluated query more than once, re-executing the underlying work or yielding inconsistent results, often avoided by materializing to a list or array
B.Deferred execution — the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
C.Deferred execution — the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
D.Deferred execution — a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls
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4. What is Multiple enumeration pitfall?
Senior
A.the performance and correctness hazard of iterating a lazily-evaluated query more than once, re-executing the underlying work or yielding inconsistent results, often avoided by materializing to a list or array
B.the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
C.the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
D.the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
Answer + AI explanation with Pro
5. Which term means: "the performance and correctness hazard of iterating a lazily-evaluated query more than once, re-executing the underlying work or yielding inconsistent results, often avoided by materializing to a list or array"?
Senior
A.Immediate execution operator
B.Query syntax
C.Multiple enumeration pitfall
D.Method syntax
Answer + AI explanation with Pro
6. Which statement is correct?
Senior
A.Multiple enumeration pitfall — the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
B.Multiple enumeration pitfall — the standard query operator that projects each element of a sequence into a new form using a transform function
C.Multiple enumeration pitfall — a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls
D.Multiple enumeration pitfall — the performance and correctness hazard of iterating a lazily-evaluated query more than once, re-executing the underlying work or yielding inconsistent results, often avoided by materializing to a list or array
Answer + AI explanation with Pro
7. What is Query syntax?
Mid
A.a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls
B.the standard query operator that folds a sequence into a single accumulated result by repeatedly applying a combining function across elements
C.the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
D.the standard query operator that projects each element of a sequence into a new form using a transform function
Answer + AI explanation with Pro
8. Which term means: "a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls"?
Mid
A.Method syntax
B.Immediate execution operator
C.Aggregate operator
D.Query syntax
Answer + AI explanation with Pro
9. Which statement is correct?
Mid
A.Query syntax — a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls
B.Query syntax — the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
C.Query syntax — the standard query operator that folds a sequence into a single accumulated result by repeatedly applying a combining function across elements
D.Query syntax — the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
Answer + AI explanation with Pro
10. What is Method syntax?
Mid
A.the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
B.a category of operators such as ToList, ToArray, Count, and First that force the query to evaluate at once rather than lazily
C.a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls
D.the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
Answer + AI explanation with Pro
11. Which term means: "the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments"?
Mid
A.Method syntax
B.Multiple enumeration pitfall
C.Aggregate operator
D.Query syntax
Answer + AI explanation with Pro
12. Which statement is correct?
Mid
A.Method syntax — the standard query operator that projects each element of a sequence into a new form using a transform function
B.Method syntax — the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
C.Method syntax — the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
D.Method syntax — a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls
Answer + AI explanation with Pro
13. What is Where operator?
Junior
A.the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
B.the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
C.the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
D.the standard query operator that folds a sequence into a single accumulated result by repeatedly applying a combining function across elements
Answer + AI explanation with Pro
14. Which term means: "the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true"?
Junior
A.Deferred execution
B.Aggregate operator
C.Where operator
D.Method syntax
Answer + AI explanation with Pro
15. Which statement is correct?
Junior
A.Where operator — a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls
B.Where operator — the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
C.Where operator — the performance and correctness hazard of iterating a lazily-evaluated query more than once, re-executing the underlying work or yielding inconsistent results, often avoided by materializing to a list or array
D.Where operator — the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
Answer + AI explanation with Pro
16. What is Select operator?
Junior
A.the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
B.a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls
C.the standard query operator that projects each element of a sequence into a new form using a transform function
D.the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
Answer + AI explanation with Pro
17. Which term means: "the standard query operator that projects each element of a sequence into a new form using a transform function"?
Junior
A.Aggregate operator
B.Immediate execution operator
C.Select operator
D.Multiple enumeration pitfall
Answer + AI explanation with Pro
18. Which statement is correct?
Junior
A.Select operator — the performance and correctness hazard of iterating a lazily-evaluated query more than once, re-executing the underlying work or yielding inconsistent results, often avoided by materializing to a list or array
B.Select operator — the standard query operator that projects each element of a sequence into a new form using a transform function
C.Select operator — the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
D.Select operator — the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
Answer + AI explanation with Pro
19. What is Aggregate operator?
Mid
A.the standard query operator that folds a sequence into a single accumulated result by repeatedly applying a combining function across elements
B.the standard query operator that projects each element of a sequence into a new form using a transform function
C.the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
D.the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
Answer + AI explanation with Pro
20. Which term means: "the standard query operator that folds a sequence into a single accumulated result by repeatedly applying a combining function across elements"?
Mid
A.Deferred execution
B.Multiple enumeration pitfall
C.Aggregate operator
D.Where operator
Answer + AI explanation with Pro
21. Which statement is correct?
Mid
A.Aggregate operator — a declarative SQL-like form, using from, where, select and similar contextual keywords, that the compiler translates into method calls
B.Aggregate operator — the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
C.Aggregate operator — the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
D.Aggregate operator — the standard query operator that folds a sequence into a single accumulated result by repeatedly applying a combining function across elements
Answer + AI explanation with Pro
22. What is Immediate execution operator?
Mid
A.a category of operators such as ToList, ToArray, Count, and First that force the query to evaluate at once rather than lazily
B.the standard query operator that filters a sequence, returning only the elements for which a supplied predicate evaluates true
C.the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
D.the standard query operator that folds a sequence into a single accumulated result by repeatedly applying a combining function across elements
Answer + AI explanation with Pro
23. Which term means: "a category of operators such as ToList, ToArray, Count, and First that force the query to evaluate at once rather than lazily"?
Mid
A.Multiple enumeration pitfall
B.Immediate execution operator
C.Deferred execution
D.Aggregate operator
Answer + AI explanation with Pro
24. Which statement is correct?
Mid
A.Immediate execution operator — the fluent form of writing queries by chaining extension-method calls that take lambda expressions as arguments
B.Immediate execution operator — a category of operators such as ToList, ToArray, Count, and First that force the query to evaluate at once rather than lazily
C.Immediate execution operator — the property of most query operators whereby the query is not evaluated when defined but only when its results are iterated, so it re-runs against current source data each enumeration
D.Immediate execution operator — the standard query operator that projects each element of a sequence into a new form using a transform function
Answer + AI explanation with Pro
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