Garbage Collection

Automatic memory management

Interview Relevant: GC algorithms and tuning
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Garbage Collection

Garbage Collection (GC) automatically reclaims memory occupied by unreachable objects.

  • Prevents memory leaks
  • Runs automatically
  • Uses reachability analysis

Code Examples

Object becomes eligible for GC

java
1
2User u = new User();
3u = null;  // Eligible for GC
4

Use Cases

  • Automatic memory management

Common Mistakes to Avoid

  • Calling System.gc() explicitly
  • Assuming GC runs immediately