Await StationISSUE #5 of 26

promises · all · allSettled · race · any

PromissaVSRace Condition Rex

Promissa saysPromise.all/allSettled/race/any combine multiple promises in different ways.

Promise.all([…]) waits for all (rejects if any do); allSettled waits for all and reports each outcome (never rejects); race settles with the first to finish (success or fail); any resolves with the first success. Use all for parallel fetches, allSettled when partial failure is OK.

Power-ups you unlock

all → all succeed (or reject fast)
allSettled → every outcome, never rejects
race → first to settle wins
any → first success wins

Race Condition Rex attacks — common mistakes

Using all when one failure shouldn’t abort (use allSettled)
Awaiting promises serially when parallel works
Confusing race (any settle) with any (first success)

Boss battleRun three timeouts in parallel with Promise.all and log when all finish.

Example code

<!doctype html><html><head><meta charset="utf-8"></head>
<body style="background:#06040d;color:#e6e0ff;font-family:monospace;padding:20px"><pre id="o"></pre>
<script>const wait=(ms,v)=>new Promise(r=>setTimeout(()=>r(v),ms));
Promise.all([wait(200,'a'),wait(400,'b'),wait(300,'c')]).then(vals=>document.getElementById('o').textContent='all done: '+vals);</script></body></html>

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