Which of the following describes a characteristic of immutability?

Which of the following describes a characteristic of immutability?

• A. A variable can change its value
• B. A variable’s value is fixed after assignment
• C. A variable has undefined state
• D. A variable can be used in any context

Answer: (B)

Immutability refers to the property of an object or variable whose value cannot be modified after it has been assigned. When a variable is said to be immutable, it means that once a value is assigned to it, that value remains constant throughout its lifecycle. This characteristic is particularly relevant in programming languages and contexts where predictability and safety are essential, such as in functional programming paradigms. In contrast, other characteristics imply flexibility and variability. For instance, a variable that can change its value indicates that it is mutable, which is the opposite of immutability. Additionally, a variable with an undefined state suggests that it does not have a clear or established value, which again contradicts the notion of immutability. Finally, the ability of a variable to be used in any context pertains more to scope or accessibility rather than its characteristics of mutability or immutability. Thus, the option that captures the essence of immutability is that a variable’s value is fixed after assignment.

Immutability refers to the property of an object or variable whose value cannot be modified after it has been assigned. When a variable is said to be immutable, it means that once a value is assigned to it, that value remains constant throughout its lifecycle. This characteristic is particularly relevant in programming languages and contexts where predictability and safety are essential, such as in functional programming paradigms.

In contrast, other characteristics imply flexibility and variability. For instance, a variable that can change its value indicates that it is mutable, which is the opposite of immutability. Additionally, a variable with an undefined state suggests that it does not have a clear or established value, which again contradicts the notion of immutability. Finally, the ability of a variable to be used in any context pertains more to scope or accessibility rather than its characteristics of mutability or immutability. Thus, the option that captures the essence of immutability is that a variable’s value is fixed after assignment.