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Welcome back.

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In this video, let's see how we can create our first promise.

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So let's get started.

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Well, let's have a look at the syntax of creating a promise.

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Well, let's go through this syntax line by line.

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We have a keyword called concept and the variable called promise.

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This variable can be anything.

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Right.

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And the clue part is what comes after the e cosine.

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We see we have a new keyword, which is a special keyword in JavaScript and we have promise for this

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promise.

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It's a function.

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Then we pass in only one element to this function.

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So this is my agreement.

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I pass in to the promise function and this one is what we call callback.

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For this one, I use every function.

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So inside a callback you see that we pass in to agreement, resolve and reject.

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So resolve and reject the ah functions well.

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So inside our promise you see that your code goes here.

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And then we call this resolve.

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If the promise is resolved and we call reject when the promise is rejected, great.

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So here it means that we are waiting to implement a code that takes some time to execute, like making

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HTTP calls.

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So in this context, we are going to mimic assuming that we are making HTTP requests.

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So let's see how we can create our first promise using code.

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So back to Visual City code.

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So let me comment.

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This one's that is a bad callback and now let me copy this one and come down here.

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This one going to be a promise.

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And here we go.

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How can we create a promise?

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So first of all, we bring new key word like that and then promise, which is a special keyword in JavaScript.

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And then inside that we pass in a callback function.

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I can pass in normal function as this or I can make use of arrow function so the choice is yours.

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So I'm going to use arrow function.

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So this function takes in only one argument.

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That's a callback function, that is an anonymous function, a function without a name.

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So inside our callback function here, we need to have access these two again main core result and then

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reject as we discussed in the previous video.

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So inside of function body now our code goes here well so remember that the resolve and then reject

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the function.

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That's why we are callback remember how we able to identify that is a callback so I can name this one

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whatever I want I can see that JavaScript or CSS or my my resolve or rejected or error or okay it can

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be anything.

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So here we have two functions and remember promise.

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Always retain either resolve or reject.

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You cannot retain two of them, let's say resolve or vector, because if you make a request, there

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are chances that we can have success or error.

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We cannot have error in success.

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So remember that we always retain one function from a promise.

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So how can we do it based on a condition?

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So what comes back?

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We need to assign to a variable.

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It can be anything by convention.

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We make this of promise equal to that.

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So with this one I have created my first promise for this one.

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There is no syntax or there's no logic going on.

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So let's say that we are making HTTP requests.

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It simply means that a request that takes some time before we can get it.

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So let's say that you want to fetch all users, let's say a user from database, so we can say that

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user is equal to simple object.

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And here you go.

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So let's say the name of this user name is going to be John.

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And then let's say the city of this person is commands can be anything of your choice.

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So this is our logic of fetching that.

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We are fetching this one from database.

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Okay, so let's have a variable called let's say it's fetched, so let's is fetched, meaning that we

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have first the data from database.

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Based on this condition, we can render any of these ones good.

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So here we are going to retain one of these.

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It means that if it's fetched, meaning we have back, we have the user.

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So here we will say that if is first is first, then we can console.log the resolve otherwise or else

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reject and then I'll bring reject here as that.

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So we see that we are turning one of these based on these conditions here.

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So now we have created our perfect promise.

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So how can we use it?

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The next video we will talk more about the resolve and then reject in the next video as well.