ES6 Variables - 2

let and const cannot be declared more than once *in the same block.

So if you accidentally name two lets or const the same in the same block, it gives an error.

If you declare an existing let inside a different block, it is allowed but creates, not redefines, a new let.

const cannot be updated. 

If an object is const, the structure of the object cannot change but its properties can change.

  const person={name:”Arjun”, age:26};

  person.age=27; 

  console.log(person); //shows age 27.

If you want the properties of an object to be unchangeable:

  const arjun=Object.freeze(person);

  arjun.age=27;

  console.log(arjun);//shows age 26

let and const

*can’t be declared more than once

*const properties can change
*Object.freeze