Understanding Variable Declaration in _JavaScript: const vs. let vs. var

🔒The const keyword is used to define variables that cannot be reassigned.

🔑The let keyword is used to define variables that are block-scoped and can be reassigned.

🌟The var keyword is used to define variables that are function-scoped and can be accessed before they are defined.

⏲️Variables defined with const and let have temporal dead zones and cannot be accessed before they are declared.

🧩const should be used for values that never change, let for block-level variables, and var for function-level variables.

What is the difference between const, let, and var in JavaScript?

—const is used for variables that cannot be reassigned, let is used for block-scoped variables that can be reassigned, and var is used for function-scoped variables that can be accessed before they are defined.

Can I reassign a value to a variable declared with const?

—No, variables declared with const cannot be reassigned.

What is a temporal dead zone?

—A temporal dead zone is a phase during the execution of a program when a variable is defined but cannot be accessed before it is declared.

When should I use const, let, and var?

—You should use const for values that never change, let for block-level variables, and var for function-level variables.

Can I access a variable declared with let or const before it is declared?

—No, variables declared with let or const have a temporal dead zone and cannot be accessed before they are declared.

00:00This video explains the differences between const, let, and var in JavaScript variable declaration.

00:10The const keyword is used for variables that cannot be reassigned.

00:55The let keyword is used for block-scoped variables.

02:00The var keyword is used for function-scoped variables.

03:28The differences between const, let, and var are summarized.