Core Principles interview questions

18 real Core Principles questions from the Functional Programming bank, as asked in Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd — free to start.

1. What is Pure function?

Junior
  1. A.a routine whose output depends only on its arguments and which causes no observable side effects
  2. B.the property that an expression can be replaced by its resulting value without changing the program's behavior
  3. C.the practice of never changing a value after it is created, producing new values instead of altering existing ones
  4. D.a way of programming that describes what result is wanted rather than the step-by-step instructions to compute it
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3. Which statement is correct?

Junior
  1. A.Pure function — any interaction with the outside world or mutation of external state that a computation performs beyond returning a value
  2. B.Pure function — a way of programming that specifies an explicit sequence of statements that change program state to reach a result
  3. C.Pure function — a routine whose output depends only on its arguments and which causes no observable side effects
  4. D.Pure function — the practice of never changing a value after it is created, producing new values instead of altering existing ones
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4. What is Side effect?

Junior
  1. A.a way of programming that describes what result is wanted rather than the step-by-step instructions to compute it
  2. B.any interaction with the outside world or mutation of external state that a computation performs beyond returning a value
  3. C.a routine whose output depends only on its arguments and which causes no observable side effects
  4. D.the practice of never changing a value after it is created, producing new values instead of altering existing ones
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5. Which term means: "any interaction with the outside world or mutation of external state that a computation performs beyond returning a value"?

Junior
  1. A.Declarative style
  2. B.Imperative style
  3. C.Referential transparency
  4. D.Side effect
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6. Which statement is correct?

Junior
  1. A.Side effect — a way of programming that specifies an explicit sequence of statements that change program state to reach a result
  2. B.Side effect — a routine whose output depends only on its arguments and which causes no observable side effects
  3. C.Side effect — a way of programming that describes what result is wanted rather than the step-by-step instructions to compute it
  4. D.Side effect — any interaction with the outside world or mutation of external state that a computation performs beyond returning a value
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7. What is Referential transparency?

Mid
  1. A.the property that an expression can be replaced by its resulting value without changing the program's behavior
  2. B.a way of programming that specifies an explicit sequence of statements that change program state to reach a result
  3. C.a routine whose output depends only on its arguments and which causes no observable side effects
  4. D.a way of programming that describes what result is wanted rather than the step-by-step instructions to compute it
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8. Which term means: "the property that an expression can be replaced by its resulting value without changing the program's behavior"?

Mid
  1. A.Pure function
  2. B.Declarative style
  3. C.Referential transparency
  4. D.Side effect
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9. Which statement is correct?

Mid
  1. A.Referential transparency — a routine whose output depends only on its arguments and which causes no observable side effects
  2. B.Referential transparency — a way of programming that describes what result is wanted rather than the step-by-step instructions to compute it
  3. C.Referential transparency — the practice of never changing a value after it is created, producing new values instead of altering existing ones
  4. D.Referential transparency — the property that an expression can be replaced by its resulting value without changing the program's behavior
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10. What is Immutability?

Junior
  1. A.a routine whose output depends only on its arguments and which causes no observable side effects
  2. B.a way of programming that describes what result is wanted rather than the step-by-step instructions to compute it
  3. C.any interaction with the outside world or mutation of external state that a computation performs beyond returning a value
  4. D.the practice of never changing a value after it is created, producing new values instead of altering existing ones
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11. Which term means: "the practice of never changing a value after it is created, producing new values instead of altering existing ones"?

Junior
  1. A.Immutability
  2. B.Pure function
  3. C.Declarative style
  4. D.Referential transparency
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12. Which statement is correct?

Junior
  1. A.Immutability — the practice of never changing a value after it is created, producing new values instead of altering existing ones
  2. B.Immutability — any interaction with the outside world or mutation of external state that a computation performs beyond returning a value
  3. C.Immutability — a way of programming that specifies an explicit sequence of statements that change program state to reach a result
  4. D.Immutability — the property that an expression can be replaced by its resulting value without changing the program's behavior
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13. What is Declarative style?

Mid
  1. A.any interaction with the outside world or mutation of external state that a computation performs beyond returning a value
  2. B.a routine whose output depends only on its arguments and which causes no observable side effects
  3. C.a way of programming that describes what result is wanted rather than the step-by-step instructions to compute it
  4. D.the practice of never changing a value after it is created, producing new values instead of altering existing ones
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14. Which term means: "a way of programming that describes what result is wanted rather than the step-by-step instructions to compute it"?

Mid
  1. A.Pure function
  2. B.Referential transparency
  3. C.Side effect
  4. D.Declarative style
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15. Which statement is correct?

Mid
  1. A.Declarative style — a way of programming that describes what result is wanted rather than the step-by-step instructions to compute it
  2. B.Declarative style — the property that an expression can be replaced by its resulting value without changing the program's behavior
  3. C.Declarative style — a routine whose output depends only on its arguments and which causes no observable side effects
  4. D.Declarative style — any interaction with the outside world or mutation of external state that a computation performs beyond returning a value
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16. What is Imperative style?

Mid
  1. A.the property that an expression can be replaced by its resulting value without changing the program's behavior
  2. B.a way of programming that specifies an explicit sequence of statements that change program state to reach a result
  3. C.a routine whose output depends only on its arguments and which causes no observable side effects
  4. D.a way of programming that describes what result is wanted rather than the step-by-step instructions to compute it
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17. Which term means: "a way of programming that specifies an explicit sequence of statements that change program state to reach a result"?

Mid
  1. A.Imperative style
  2. B.Declarative style
  3. C.Side effect
  4. D.Referential transparency
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18. Which statement is correct?

Mid
  1. A.Imperative style — the practice of never changing a value after it is created, producing new values instead of altering existing ones
  2. B.Imperative style — a way of programming that specifies an explicit sequence of statements that change program state to reach a result
  3. C.Imperative style — any interaction with the outside world or mutation of external state that a computation performs beyond returning a value
  4. D.Imperative style — a way of programming that describes what result is wanted rather than the step-by-step instructions to compute it
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