java memory usage

Question

how the java memory works whenever a new class is instantiated, and when it gets garbage collected, etc.

And also there is difference in memory usage for the collection classes. For eg:Vector takes more memory than hash map like that.

Thanks in advance

This question is far too vague. – Stephen C Dec 10 '10 at 07:25 — Stephen C, Dec 10 '10 at 07:25

score 3 · Answer 1 · answered Dec 10 '10 at 07:33

3

Classes are not instantiated, rather classes are defined and objects from those classes are instantiated. when a object is instantiated using new operator memory is allocated.

answered Dec 10 '10 at 07:33

Nipuna

6,176
8
62
86

score 1 · Accepted Answer · answered Dec 10 '10 at 07:40

1

When a new object is instantiated it takes up memory, when it is no longer used, it frees up memory. More items you put in a collection more memory it will take. When you no longer need an object you want to set to null.

answered Dec 10 '10 at 07:40

fastcodejava

37,849
27
129
182

1

This probably isn't true anymore. See this question: http://stackoverflow.com/questions/850878/does-setting-java-objects-to-null-do-anything-anymore – Feanor Dec 10 '10 at 07:58

java memory usage

2 Answers2