Here is a great JavaScript interview question!
What the heck is a Promise doing under the hood?
In JavaScript, things usually happen one after the other. It's like a checklist each item gets done before moving to the next.
When a function returns a Promise, it's like making a promise to do something, like fetch data from the internet. But JavaScript doesn't wait around for the data to come back. Instead, it moves on to the next task.
Now, here's where things get interesting. While JavaScript is busy doing other stuff, like running more code, the Promise is off fetching data in the background.
Once the data is fetched, the Promise is fulfilled, and it has some information to share. But JavaScript needs to know when it's time to handle that information. That's where the onFulfilled part of the Promise comes in.
When the Promise is fulfilled, JavaScript takes the onFulfilled code and puts it in a special queue, ready to be run.
Now, async/await enters the scene. When we mark a function as async, we're telling JavaScript, "Hey, this function might take some time to finish, so don't wait up for it."
And when we use the await keyword inside an async function, it's like saying, "Hold on a sec, JavaScript. I need to wait for something important before moving on."
So, when JavaScript encounters an await keyword, it pauses and lets the async function do its thing. If that thing happens to be a Promise, JavaScript knows it can move on to other tasks while waiting for the Promise to resolve.
Once the Promise is resolved, JavaScript picks up where it left off and continues running the code.
Promises and async/await allow JavaScript to handle asynchronous tasks while keeping things organized and in order. Promises handle the background tasks, while async/await makes it easier to work with them in our code, ensuring everything happens in the right sequence.
Web Development Best Resources: https://topmate.io/coding/930165
ENJOY LEARNING 👍👍
What the heck is a Promise doing under the hood?
In JavaScript, things usually happen one after the other. It's like a checklist each item gets done before moving to the next.
When a function returns a Promise, it's like making a promise to do something, like fetch data from the internet. But JavaScript doesn't wait around for the data to come back. Instead, it moves on to the next task.
Now, here's where things get interesting. While JavaScript is busy doing other stuff, like running more code, the Promise is off fetching data in the background.
Once the data is fetched, the Promise is fulfilled, and it has some information to share. But JavaScript needs to know when it's time to handle that information. That's where the onFulfilled part of the Promise comes in.
When the Promise is fulfilled, JavaScript takes the onFulfilled code and puts it in a special queue, ready to be run.
Now, async/await enters the scene. When we mark a function as async, we're telling JavaScript, "Hey, this function might take some time to finish, so don't wait up for it."
And when we use the await keyword inside an async function, it's like saying, "Hold on a sec, JavaScript. I need to wait for something important before moving on."
So, when JavaScript encounters an await keyword, it pauses and lets the async function do its thing. If that thing happens to be a Promise, JavaScript knows it can move on to other tasks while waiting for the Promise to resolve.
Once the Promise is resolved, JavaScript picks up where it left off and continues running the code.
Promises and async/await allow JavaScript to handle asynchronous tasks while keeping things organized and in order. Promises handle the background tasks, while async/await makes it easier to work with them in our code, ensuring everything happens in the right sequence.
Web Development Best Resources: https://topmate.io/coding/930165
ENJOY LEARNING 👍👍
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⚡️ Understanding the 5 loops of JavaScript
🔁 Loops offer a quick & easy way to do something repeatedly.
1. JavaScript For loop
Repeats a block of code as long as a certain condition is met.
Typically, used to loop through a block of code a specific amount of times.
2. JavaScript while loop
Loops through a block of code as long as the specified condition evaluates to true. As soon as the condition fails, the loop is stopped.
3. JavaScript do…while loop
The do…while loop is a variant of the while loop, which evaluates the condition at the END of each loop iteration.
With a do…while loop the block of code is executed ONCE, and THEN the condition is evaluated.
🔁 Loops offer a quick & easy way to do something repeatedly.
The 5 loops in JavaScript essentially do the same thing: — they repeat an action a certain number of times. However, they have important differences.
Let’s dive in!
1. JavaScript For loop
Repeats a block of code as long as a certain condition is met.
Typically, used to loop through a block of code a specific amount of times.
2. JavaScript while loop
Loops through a block of code as long as the specified condition evaluates to true. As soon as the condition fails, the loop is stopped.
3. JavaScript do…while loop
The do…while loop is a variant of the while loop, which evaluates the condition at the END of each loop iteration.
With a do…while loop the block of code is executed ONCE, and THEN the condition is evaluated.
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