JavaScript #1: Control hoisting JavaScript easily!

If you are finding hoisting confusing, here is an article to help you understand hoisting better.

According to the definition of hoisting, the Java Script engine excutes divides into two phases, one is to initialize variables and functions, the other is to assign values to variables and functions.

Hoisting refers to the process whereby the interpreter allocates memory variable and function declarations prior to execute the code.

And hoisting occurs when variables or functions are called before being initialized. And when the JavaScript engine executes it puts the initialization variables and functions first.

Look at the example below with var when initialized variable:

Try to guess what the outcome will be?

This means that when initializing the engine variable Java Script initializes the variable first and assigns it the value undefined before executing console.log().

It would be like something like this:

So let's try to initialize with let(const) and do the same thing as above:

And again, guess what will happen?

If your guess is wrong then you have a correct answer, if not, that's okay because I'll show you where the difference lies:

The above let(const) initialization would be similar to something like this:

But the interesting thing is that when initialized with let(const), the variable will be put into the "tempotal dead zone", simply understood that this variable will not be able to be used without being assigned a value. Besides, it also means not assigning undefined as var.

Let's try with initialized function will be like?

And guess what the outcome will be?

Wow! It's interesting. So what's the difference between the function and the above?

One of the advantages of JavaScript putting function declarations into memory before it executes any code segment is that it allows you to use a function before you declare it in your code.<< Developer Mozilla >>

It means that you would execute the function above like this: