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Basic Types interview questions

18 real Basic Types questions from the TypeScript 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 any?

Junior
  1. A.a type that opts out of type checking — assignable to and from any other type, disabling safety
  2. B.the type of values that never occur, such as a function that always throws or an exhausted union
  3. C.the absence of a return value — the type of a function that returns nothing
  4. D.an array type with a fixed length and a known type at each position
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3. Which statement is correct?

Junior
  1. A.any — a type-safe counterpart to any: you must narrow it before you can use the value
  2. B.any — a named set of constant values, numeric by default, compiled to a real runtime object
  3. C.any — a type that opts out of type checking — assignable to and from any other type, disabling safety
  4. D.any — the absence of a return value — the type of a function that returns nothing
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4. What is unknown?

Mid
  1. A.an array type with a fixed length and a known type at each position
  2. B.a type-safe counterpart to any: you must narrow it before you can use the value
  3. C.a type that opts out of type checking — assignable to and from any other type, disabling safety
  4. D.the absence of a return value — the type of a function that returns nothing
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6. Which statement is correct?

Mid
  1. A.unknown — a named set of constant values, numeric by default, compiled to a real runtime object
  2. B.unknown — a type that opts out of type checking — assignable to and from any other type, disabling safety
  3. C.unknown — an array type with a fixed length and a known type at each position
  4. D.unknown — a type-safe counterpart to any: you must narrow it before you can use the value
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7. What is never?

Mid
  1. A.the type of values that never occur, such as a function that always throws or an exhausted union
  2. B.a named set of constant values, numeric by default, compiled to a real runtime object
  3. C.a type that opts out of type checking — assignable to and from any other type, disabling safety
  4. D.an array type with a fixed length and a known type at each position
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9. Which statement is correct?

Mid
  1. A.never — a type that opts out of type checking — assignable to and from any other type, disabling safety
  2. B.never — an array type with a fixed length and a known type at each position
  3. C.never — the absence of a return value — the type of a function that returns nothing
  4. D.never — the type of values that never occur, such as a function that always throws or an exhausted union
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10. What is void?

Junior
  1. A.a type that opts out of type checking — assignable to and from any other type, disabling safety
  2. B.an array type with a fixed length and a known type at each position
  3. C.a type-safe counterpart to any: you must narrow it before you can use the value
  4. D.the absence of a return value — the type of a function that returns nothing
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12. Which statement is correct?

Junior
  1. A.void — the absence of a return value — the type of a function that returns nothing
  2. B.void — a type-safe counterpart to any: you must narrow it before you can use the value
  3. C.void — a named set of constant values, numeric by default, compiled to a real runtime object
  4. D.void — the type of values that never occur, such as a function that always throws or an exhausted union
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13. What is tuple?

Junior
  1. A.a type-safe counterpart to any: you must narrow it before you can use the value
  2. B.a type that opts out of type checking — assignable to and from any other type, disabling safety
  3. C.an array type with a fixed length and a known type at each position
  4. D.the absence of a return value — the type of a function that returns nothing
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15. Which statement is correct?

Junior
  1. A.tuple — an array type with a fixed length and a known type at each position
  2. B.tuple — the type of values that never occur, such as a function that always throws or an exhausted union
  3. C.tuple — a type that opts out of type checking — assignable to and from any other type, disabling safety
  4. D.tuple — a type-safe counterpart to any: you must narrow it before you can use the value
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16. What is enum?

Junior
  1. A.the type of values that never occur, such as a function that always throws or an exhausted union
  2. B.a named set of constant values, numeric by default, compiled to a real runtime object
  3. C.a type that opts out of type checking — assignable to and from any other type, disabling safety
  4. D.an array type with a fixed length and a known type at each position
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18. Which statement is correct?

Junior
  1. A.enum — the absence of a return value — the type of a function that returns nothing
  2. B.enum — a named set of constant values, numeric by default, compiled to a real runtime object
  3. C.enum — a type-safe counterpart to any: you must narrow it before you can use the value
  4. D.enum — an array type with a fixed length and a known type at each position
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Interfaces & Types (18)Generics (18)Narrowing & Guards (18)Utility & Composite Types (18)