Async/Await Syntax

What is the key difference between these two functions?

async function processItems(items) {
  const results = [];
  for (const item of items) {
    results.push(await processItem(item));
  }
  return results;
}

async function processItemsParallel(items) {
  return Promise.all(items.map(item => processItem(item)));
}

Error handling approach
Return value type
Execution order guarantee
The key difference is execution order guarantee: 1) processItems processes items sequentially, guaranteeing order, 2) processItemsParallel processes all items in parallel with no order guarantee, 3) Sequential processing is slower but predictable, 4) Parallel processing is faster but may complete in any order, 5) Sequential processing may be needed for dependent operations, 6) Choose based on whether order and item independence matter.
Memory usage

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