CODEWITHSUNDEEP
javaperformancejvm
socksocket
socksocket

Reputation: 4371

JAVA: reference defined within a loop

I'm just curious.
suppose I define a reference inside a while/for loop.

does the JVM define this reference every iteration, or it's optimized to define it only once?

Upvotes: 7

Views: 232

Answers (4)

Kumar Vivek Mitra
Kumar Vivek Mitra

Reputation: 33544

- The defines the reference everytime the loop iterates, but the scope of the reference is attached only to that iteration.

- Consider that you have declared a reference outside the loop, but assign object to it inside the loop, then the reference remains the same , but it reference new object of that type in every iteration.

Upvotes: 1

kosa
kosa

Reputation: 66677

It defines every time and scoped to only that loop iteration.

As soon as loop iteration done, it is eligible for GC.

As Louis Wasserman commented, The variable will be reinitialized every time, but the memory space will probably get reused.

Upvotes: 7

Peter Lawrey
Peter Lawrey

Reputation: 533880

The reference is defined on each iteration. Once the code has been optimised to native code, it could be moved outside the loop so it doesn't have to have a performance impact. If you set this reference to a new object each time, it may create a new object on each iteration unless that object creation has been optimised away also.

Upvotes: 4

Joseph Elcid
Joseph Elcid

Reputation: 877

Its defined every time. There is no optimization for that (to my knowledge).

Upvotes: 2

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