setTimeout(0), alone — interactive event loop example
1console.log('before');2 3setTimeout(() => {4 console.log('later');5}, 0);6 7console.log('after');The script starts on the call stack. console.log("before") runs synchronously.
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Call stack
script
Web APIs — browser land
The event loop — is the call stack empty? → drain the microtask queue first → then take one callback.
Microtask queue — priority
Callback queue
Console
01before
Fig. — setTimeout(0), alone · step 1 of 7
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