ESC 6 variable and string part 2

const

const variables have the same scope as variables declared using let. The difference is that const variables are immutable - they are not allowed to be reassigned.
For example, the following generates an exception:

const a = 'Hello';
a = 'Bye';Try It Yourself

const is not subject to Variable Hoisting too, which means that const declarations do not move to the top of the current execution context.
Also note that ES6 code will run only in browsers that support it. Older devices and browsers that do not support ES6 will return a syntax error.