js var vs const 1

js var vs const

//var variables can be re-declared and updated
    var greeter = "hey hi";
    var greeter = "say Hello instead";
//it becomes a problem when you do not realize that a variable 
//greeter has already been defined before.

//const declarations are block scoped
//const cannot be updated or re-declared
	const greeting = "say Hi";
	greeting = "say Hello instead";// error: Assignment to constant variable. 

	const greeting = "say Hi";
	const greeting = "say Hello instead";// error: Identifier 'greeting' has already been declared

Here is what the above code is Doing:
1. The const declaration creates a read-only reference to a value. It does not mean the value it holds is immutable, just that the variable identifier cannot be reassigned. For instance, in the case where the content is an object, this means the object’s contents (e.g., its properties) can be altered.
2. The const declaration, like let, is block scoped.
3. The const declaration must be initialized at the time of declaration.

Similar Posts