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Welcome back.

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And this video is all about async await.

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Well, async await is also another way of writing async code.

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Now, you talk about callbacks, promises, and now we are on async await.

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Async await is most commonly used among promises and callbacks.

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So in this video, let's see how we are going to make use of async await, which is a new feature that

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has been shaped into the JavaScript language.

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So how can we use async await and when do we need to use it?

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So in this particular video, let's see in details what is saying await is or about.

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Before we get into it, let's look at the syntax of writing is saying I wait for this particular function,

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let's see what is going on here.

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You could see that we have a special keyword called async and then after that we bring our function

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keyword and the function name where and inside the function.

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The difference here is we have a new keyword called await and then we have a function call, for example,

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make API requests.

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So before we get into this, how we are going to code from scratch using async await, let's have a

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look at the rules governing async await.

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The first point says that it adjusts like a syntactic sugar for promises, meaning that whether it's

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a promise or async await, they have the same logic.

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But the syntax that differs.

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Nothing has been changed into the logic.

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Everything is the same, but the syntax that differ.

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That is why we say is that just like a syntactic sugar for promises.

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And apart from that you also have the weight keyword and it's only valid inside async functions.

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It simply means that we only use a weight when we mark our function as an async.

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So coming back to this, you could say that for this particular function we have async.

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That's why we are able to use a weight inside this function.

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So again, a weight is valid inside async function and its function is a function that has a special

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keyword called async before the function name.

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So let's continue.

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Well, the next point is that async function must start with async keyword, and that is what we have

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done.

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We have what, async here.

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So let's continue on.

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The next point is that a weight is put in front of any promise based API call or function that will

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take some time to complete.

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So the trick part here is that sometimes we get confused when to use a weight.

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Well, the key note here is that we use a weight in front of any function or any code that needs some

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time to complete, for example, making it HTTP calls.

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So if we say that we have a function called make API call request, and for this one we're going to

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take some time.

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That's why we added a weight in front of it.

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So any code in your code base that needs some time to execute, you need to mark or put a weight in

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front of it.

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So our simply means that I'm waiting for you.

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Just go and make the request when you finish, then I'll give back the value and assigned a variable

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called response.

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That is it about the weight keyword what it does.

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The next point is that async function returns a promise that one we've talked about it before and promises

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always async function returns a promise.

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So in that case we need to watch, consume or resolve it, use it to then when it goes to, let's say

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the promises you use then and cache for that but for async await, let's see what we need.

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Great for async await we use try and catch again.

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Try and catch to handle success and error, remember.

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So in case of promise we make keys of resolve when a promise is success, but for async await instead

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of resolve, we're going to use try and instead of reject in promise, we are going to use catch to

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handle those responses.

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That comes back when you make an API requests and lastly use async, await to wait for the promise to

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resolve like I've said.

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All right, so with this one in mind in this video, let's see how we are going to write our first async.

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With passion.

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Let's get rocking the next video.