Java garbage collection

Question

Java automatically calls garbage collector, then why we need manual calls for garbage collection? When should use System.gc()

Answer 1

There isn't a need to call for garbage collection explicitly and calling System.gc() is only a suggestion, the JVM can ignore your suggestion.

The only practical uses I can think of is

1. During debugging, forcing a collection can expose a memory leak
2. If the program goes through predictable cycles of intense computation followed by no computation (like a turn based game), during the no-computation period the CPU could be utilized for a suggested garbage collection to prevent jitter during the intense computation portions.