Bits of .NET

This is NOT about micro-optimizations.
It’s about callback overhead.

Example

items.forEach(item => process(item));

vs

for (let i = 0; i < items.length; i++) {
  process(items[i]);
}

Why

• forEach creates a function call per iteration

• Harder for JS engines to optimize

• No early break support

When it matters

• Large arrays

• Hot paths

• Real-time processing

Rule
Readability first.
But measure before choosing.