[Easy] LeetCode JS 30 - 2621. Sleep

Question Prompt

JavaScript has a built-in setTimeout to pause and resume code, but it's a bit awkward to use. Can we make it work more smoothly, like the 'sleep' function in other languages such as Java and Python but in an asynchronous way?

// we can do
console.log("Explain");
await sleep(3000); // Pause for 3 second
console.log("This");

// or do
console.log("Explain");
sleep(3000).then(() => {
  console.log("This"); // Only logs after 3 seconds
});

Solutions

We can implement sleep in the following steps:

1. Declares a function named sleep that expects a duration (in milliseconds) as input. The async keyword makes this function asynchronous, meaning it can handle tasks that take time without blocking the main thread.
2. Creates a new Promise object, which is a way to manage asynchronous operations. The Promise constructor takes a callback function (called the executor) that handles how the Promise will be resolved or rejected.
3. Schedules a timeout using JavaScript's built-in setTimeout function. After the specified duration in milliseconds, the resolve function will be called. resolve is a function provided by the Promise object, used to indicate that the asynchronous operation has completed successfully.
4. Lastly, returns the created Promise object, allowing other parts of the code to interact with it and wait for the sleep to finish.

async function sleep(duration) {
  return new Promise((resolve) => setTimeout(resolve, duration));
}