Understanding memory management is crucial for writing efficient JavaScript. Let's dive in.

Automatic, But Not Magical

JavaScript handles memory allocation and deallocation automatically, but it's not infallible.

let obj = { data: "huge" }; // Memory allocated
obj = null; // Memory eligible for GC, but not immediately freed

The Garbage Collector (GC)

Two main algorithms:

1. Reference Counting (old, flawed)
2. Mark-and-Sweep (modern, effective)

GC runs periodically, not instantly.

Common Memory Leaks

1. Accidental globals

function leak() {
  oops = "I'm global!";
}

1. Forgotten timers

setInterval(() => {
  // Holds references even when unused
}, 1000);

1. Closures holding large scopes

function factory(largeData) {
  return () => console.log(largeData);
}

Best Practices

1. Use const and let, avoid var
2. Nullify references when done
3. Be cautious with event listeners

element.addEventListener('click', handler);
// Later:
element.removeEventListener('click', handler);

Tools for Memory Analysis

• Chrome DevTools Memory panel
• Node.js --inspect flag

Performance Tips

1. Reuse objects instead of creating new ones
2. Use object pools for frequent allocations/deallocations
3. Avoid deep nested functions (flatten when possible)

Remember: Premature optimization is the root of all evil. Profile first, optimize second.

Cheers🥂