What keyword is used to define a constant in JavaScript?

In JavaScript, the keyword used to define a constant is "const." When you declare a variable with "const," it must be initialized at the time of declaration, and its value cannot be reassigned later in the code. This ensures that the variable remains constant throughout its scope, providing a level of safety against unintentional changes.

Using "const" is particularly beneficial in cases where you want to maintain a fixed reference, such as when working with configuration values or constants that shouldn't change during the execution of the program. Unlike "let" and "var," which allow for reassignment, "const" serves as a clear indicator to other developers that the value should remain constant, enhancing code readability and maintainability.

The other keywords—"let" and "var"—are used to declare variables that can be changed after their initial assignment, making them unsuitable for defining constants. The term "constant" is not a keyword in JavaScript; hence it cannot be used to declare a constant value.