const block scope javascript code example

Example 1: const let var scope

var num = 1;   //var can be function or global scoped
const num = 2; //const can only be block scoped
let num = 3;   //let can only be block scoped

Example 2: const { message }

const { bar } = foo; // where foo = { bar:5, baz:2, bat: 10 };
/* This creates a constant with the name 'bar', which has a value of 5 */
const { message } = new assert.AssertionError({
  actual: 1,
  expected: 2,
  operator: 'strictEqual'
});