Await JS code example

Example 1: await js

// Just watch here https://youtu.be/V_Kr9OSfDeU
// You'll understand in like 7 mins.

Example 2: async await

const data = async ()  => {
  const got = await fetch('https://jsonplaceholder.typicode.com/todos/1');
  
  console.log(await got.json())
}

data();

Example 3: how to make an async function

function resolveAfter2Seconds() {
  return new Promise(resolve => {
    setTimeout(() => {
      resolve('resolved');
    }, 2000);
  });
}

//async function:
async function asyncCall() {
  console.log('calling');
  const result = await resolveAfter2Seconds();
  console.log(result);
  // expected output: 'resolved'
}

asyncCall();

Example 4: async await javascript

function hello() {
  return new Promise((resolve,reject) => {
    setTimeout(() => {
      resolve('I am adam.');
    }, 2000);
  });
}
async function async_msg() {
  try {
    let msg = await hello();
    console.log(msg);
  }
  catch(e) {
    console.log('Error!', e);
  }
}
async_msg(); //output - I am adam.

Example 5: await in node js

// server.js

function square(x) {
  return new Promise(resolve => {
    setTimeout(() => {
      resolve(Math.pow(x, 2));
    }, 2000);
  });
}

async function layer(x)
{
  const value = await square(x);
  console.log(value);
}

layer(10);

Example 6: js async await

/* Notes:
	1. written like synchronous code
    2. compatible with try/catch blocks
    3. avoids chaining .then statements
    4. async functions always return a promise
    5. function pauses on each await expression
    6. A non promise value is converted to 
       Promise.resolve(value) and then resolved
*/

// Syntax
// Function Declaration
async function myFunction(){
  await ... // some code goes here
}
  
// Arrow Declaration
const myFunction2 = async () => {
  await ... // some code goes here
}
  
 // OBJECT METHODS

const obj = {
	async getName() {
		return fetch('https://www.example.com');
	}
}

// IN A CLASS

class Obj {
	// getters and setter CANNOT be async
	async getResource {
		return fetch('https://www.example.com');
	}
}