CODEWITHSUNDEEP
javascriptasynchronouswhile-loopsettimeout
Islero
Islero

Reputation: 3

While loop with an async setTimeout function

I have a problem. My code doesn't work. It doesn't display the last essage in the console.log (the "end"). I use a setTimeout promise to do one thing every 3000ms. Here is my promise function setTimeOut

function delay(message){
    return new Promise(() => setTimeout(function () {
        console.log(message)
    }, 3000))
}

That I use in an async function in my code :

async () => {
    while (true) {
        console.log("Start")
        await delay("No")
        console.log("End")
    }
}

I make my code more easier (without all the conditions and the functions that I have to call) because I think I've missed something in my understanding of the promise maybe. What am i doing wrong?

Could you please help me for this?

Upvotes: 0

Views: 2639

Answers (1)

fjc
fjc

Reputation: 5815

Your promise in delay/timeout function never resolves.

Here's how it will work. Note the resolve parameter of the promise callback.

function delay(message) {
    return new Promise((resolve) => setTimeout(function () {
        console.log(message);
        resolve();
    }, 3000))
}
    
(async () => {
    while (true) {
        console.log("Start")
        await delay("No")
        console.log("End")
    }
})();

Upvotes: 3

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