Which symbol is used to declare a variable in JavaScript?

In JavaScript, variables can be declared using the keywords var, let, or const. Each of these keywords serves a specific purpose.

The var keyword is used to declare variables that can be re-assigned and can have their scope defined by the nearest function block or globally if declared outside of any function. The let keyword allows you to declare block-scoped variables that can also be re-assigned. This is particularly useful in situations where you want to limit the variable's scope to a certain block of code, such as loops or conditional statements. The const keyword is used to declare variables that are block-scoped and cannot be re-assigned after their initial value has been set.

In contrast, the other options do not represent valid ways to declare variables in JavaScript. The term int is typically used in languages such as Java or C to define integer types, but it is not a keyword for declaring variables in JavaScript. declare and define are not recognized keywords in JavaScript for variable declaration. Therefore, the correct answer reflects the valid ways to declare variables in the JavaScript programming language, making it the definitive choice.