In JavaScript, how is a variable typically declared?

In JavaScript, variables are typically declared using the keywords 'let', 'const', or 'var'. These keywords provide different ways to define variables with various levels of scope and mutability.

The 'let' keyword allows you to create a block-scoped variable that can be reassigned, meaning its value can be changed after it has been assigned. This is useful in situations where the variable's value needs to be updated in a particular context, such as within loops or conditional statements.

The 'const' keyword is used to declare variables that are block-scoped and cannot be reassigned after their initial assignment. This is often used when you want to ensure that the variable's reference remains constant throughout the code, offering more predictable behavior.

The 'var' keyword is an older way to declare variables that can be reassigned as well, but it has function scope rather than block scope. This means that a variable declared with 'var' is available throughout the function in which it was declared.

The other provided answer options do not correspond to standard JavaScript syntax for declaring variables, making them invalid choices. Understanding how to properly declare variables in JavaScript is foundational for managing data and controlling the flow of your program effectively.