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Which of the following statements is FALSE?

  1. In statically typed languages, each variable in a program has a fixed type
  2. In un-typed languages, values do not have any types
  3. In dynamically typed languages, variables have no types
  4. In all statically typed languages, each variable in a program is associated with values of only a single type during the execution of the program

4 Answers

Best answer
32 votes
32 votes

Answer is (C). In dynamically typed languages variables do have type- just that it is inferred during runtime.

edited by
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10 votes

Detailed explanation on geeksforgeeks

This is an ambiguous question. “Untyped language” has no standard well-formulated definition, thus answering this question would be a bit difficult.

(A) Statically typed languages have one type associated to a variable, which is fixed once it has been deduced. Though, types could either be specified while code editing by the coder (Eg. C, Java), or it can be inferred at compile time (Eg. C++11, Haskell). Hence, after compile-time, every variable is bound to one fixed type, making this statement [TRUE]

(B) According to one definition, un-type languages store values in form of bits, thus neither variables nor values have any types associated to them. Hence this statement becomes [TRUE]

(C) Dynamically typed languages deduce types of values and bind them to the variables storing those values. Hence, values sure have fixed types, but variables don’t have fixed types bound to them. Although we can say that binding a type to a variable according to values makes them typeful, but they don’t have one fixed type. This statement has some ambiguity. [TRUE/FALSE]

(D) Same reason as of (A) [TRUE]

Hence, correct answer should be (C)

1 votes
1 votes

For More Context:

"Typed" and "untyped" are terms used to describe how programming languages handle data types and type checking. Let's explore the differences between typed and untyped languages:

Typed Languages:

  1. Static Typing: In typed languages, variables are associated with data types (e.g., integers, strings, arrays) at compile-time. This means that the type of a variable is known before the program runs. If you declare a variable to be an integer, it will always be an integer.
  2. Strong Typing: In typed languages, type safety is enforced rigorously. Operations on variables are performed based on their declared types, and the compiler checks for type compatibility. This can help catch type-related errors at compile-time.
  3. Examples: Java, C++, Swift, and TypeScript are statically typed languages. They require you to declare the type of each variable explicitly.

Untyped (or Dynamically Typed) Languages:

  1. Dynamic Typing: In untyped languages, data types are associated with values, not variables. A variable can hold different types of values during runtime. The type is determined when the value is assigned to the variable.
  2. Weak Typing: In untyped languages, type conversions and operations are not strictly enforced. You can perform operations on variables without explicit type declarations, and type coercion may occur implicitly.
  3. Examples: Python, JavaScript, Ruby, and PHP are dynamically typed languages. They allow you to change the type of a variable at runtime.

Benefits and Trade-offs:

Typed Languages:

  • Type Safety: Static typing can catch type-related errors at compile-time, making code more reliable.
  • Performance: Type information can lead to more efficient compiled code.
  • Code Documentation: Type annotations provide clear documentation.

Untyped Languages:

  • Flexibility: Dynamic typing allows for more flexible and concise code.
  • Rapid Development: You can quickly write and test code without specifying types.
  • Interoperability: Dynamic languages can easily interface with libraries and external data.

In practice, many modern programming languages offer a middle ground. For example, languages like Python and JavaScript are dynamically typed but also support optional type annotations (TypeScript for JavaScript, or Python's type hints). This provides the benefits of static typing while maintaining some flexibility.

The choice between typed and untyped languages often depends on the specific requirements of a project, developer preferences, and the development team's goals.

–1 votes
–1 votes
Answer is a.
Answer:

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