All language subtitles for 2- Constants

Alright now let's

declare a variable called interest rate. So let

interestRate and we set this to .

3. Now this is the initial value, we can always change that

later, so, we can set interest rate to let's say 1,

now if you log this on the console, of course

we're going to see the new value, right? So save the changes, and here's

one on the console. However, on a real world application,

there are situations that we don't want the value of a variable to change.

Because otherwise it's going to create all kinds of bugs in our

application. In those situations, instead of a variable, we

use a constant. So the value of a variable as

the name implies, can change, but the value of a constant cannot change.

So here, if we change let

to const. Now interestRate will be constant.

So, when I save the changes, we're going to see an error

in the console on line 3, where we reassign

interestRate. So let's have a look. Save the changes. And here's the error.

Uncaught typeError assignment to constant

variable. You can see this error happened in index.js

line 3, now if you click here, you can

see the line in code where this error occurred. So we cannot

reassign a constant. Alright now, back to the constant.

So, here is the best practice, if you don't need to reassign

constant should be your default choice. Otherwise

if you need to reassign a variable, use let.