TIL13 - JS - Variables

The 3 Keywords for Declaring a Variable

*In Javascript, there are 3 keywords you can use to declare a varible:

• var
• let
• const

Starting with ES6, the let and const keywords are used, making the var keyword almost obsolete in usage. Using let and const is preferred.

When a variable is assigned a value with one of the above keywords, the variable is said to be initialized with the assigned value

let

• Variables assigned a value using the let keyword can be re-assigned to a different value
• You can declare a variable with let without assigning a value to the variable name
  > In this case, the variable is automatically initialized with a default value of undefined.

The var keyword functions similarly to let

const

• Variables declared with const keyword cannot be re-assigned
  > const stands for "constant"
  > trying to re-assign a value to a const declared variable yields TypeError
• A const variable must be initialized with a value
  > declaring a const variable without a value yields SyntaxError