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Gajender Tyagi
Gajender Tyagi

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Job Q V/S Callback Q

🥊 Who wins when we have tasks waiting to be implemented in Job queue as well as in Callback queue.

Hmmmm.... let's see who wins with the piece of code below. 🔈

// setTimeout is a web API which waits for the time as given // in 2nd parameter and then moves the callback function in 
// call back queue   
setTimeout(() => console.log('1'), 0);
setTimeout(() => console.log('2'), 10);

// Promise is a class in JavaScript so the functionality is 
// native, to handle the functions executed we have a Job 
// queue
Promise.resolve('hi').then((data) => console.log('3'))


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If you execute this code the logs will be

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This proves that JobQ has priority over callback queue if call stack is empty, Of course!.

Thoughts in comments

🦕 ⌨️

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