如何在 JavaScript 中依次执行 Console.log 和 setTimeout

Question

(function() {
    console.log(1); 
    setTimeout(function(){console.log(2)}, 1000); 
    setTimeout(function(){console.log(3)}, 0); 
    console.log(4);
})();

Hello All,

When I run the above code, it produces the following output: 1,4,2,3

So, instead of producing 1,4,2,3 I want the output to be 1,2,3,4 but by using setTimeout() method only.

Can anyone please help me out on how to produce 1,2,3,4 by having setTimeout() method and making modifications to it.

Answer 1

To simplify things.. wrap the setTimeout with a Promise - that will give you the ability to also use async and await keywords and simplify your logic

 (async function() { function sleep(interval) { return new Promise(resolve => { setTimeout(resolve, interval) }) } console.log(1) await sleep(1000) console.log(2) await sleep(1000) console.log(3) await sleep(1000) console.log(4) })();