async/await loops

async.js

'use strict';

const delay = () => new Promise((resolve) => setTimeout(resolve, 300));

const delayedLog = async (item) => {
    await delay();
    console.log(item);
};

const processArray = (array) => {
    array.forEach(async (item) => {
        await delayedLog(item);
    });
    console.log('done');
};

const processArray1 = async (array) => {
    for (const item of array) {
        await delayedLog(item);
    }
    console.log('done');
};

const processArray2 = async (array) => {
    const promises = array.map(delayedLog);
    await Promise.all(promises);
    console.log('done');
};

processArray([1, 2, 3]);
/*
done
1
2
3
*/
processArray1([1, 2, 3]);
/*
1
2
3
done
*/
processArray2([1, 2, 3]); // fastest 
/*
1
2
3
done
*/