What are the consequences of full memory fill-up in the heap during program execution?

If the heap area is completely filled during program execution, the JVM will not be able to allocate memory for new objects. This leads to an java.lang.OutOfMemoryError: Java heap space error.

Consequences:

• The program may terminate unexpectedly with an OutOfMemoryError.
• Performance may sharply decrease due to frequent garbage collections (GC) trying to free memory.
• Data loss or incorrect application behavior may occur.

To resolve the issue, either increase the heap size or optimize memory usage (for example, reduce the number of created objects, fix memory leaks).