reference « primitive « Java Data Type Q&A

1. Why is it important to understand the difference between reference types and primitive types in Java?

I'm after a list of issues in Java that cannot be properly understood without first understanding the difference. For example:

  • Passing parameters to methods
  • Precisely what limitations are imposed by using "final" ...

2. When to use primitive and when reference types in Java

In which case should you use primitive types(int) or reference types (Integer)? This question sparked my curiosity.

3. References to java programs coded using primitives only

I've heard of Java programs with strict latency requirements where "new" instructions are never -or very rarely- used (because no new=>no objects->no GC=>improved latency)... instead all business logic is handled using ...

4. How do I pass a primitive data type by reference?

For example, how do I make an int passed to a function modifiable. Thanks in advance

5. Passing primitive data by reference in Java

is it possible to pass primitive data to a method as argument in java, without wrapping them into corresponding class objects ???

6. Java - Reference primitive data-type?

I know that with the following, a reference is made

public class MyClass
  public Integer value;

public class Main
  public static void main( String[] args )

7. Creating reference to a primitive - Roberts-Heller's cert guide?

I think the point that the example is trying to illustrate is that a copy of the *reference* to the integer array is passed into the method on the stack, not a separate copy of the array itself. So when in the method the value of the array element is changed, the original is changed. If a copy of the array ...

8. Passing primitive types by reference

I agree with Luigi. There's never a good reason to do this. A much more robust way is to call a method that returns a primitive value based on the primitive you passed to it. The caller can then reassign the variable passed with the value returned. Avoid methods with side-effects if you can.

9. achieveing 'by reference' in java for primitives

Besides, there's no way you'd want to have a side-effect like that, even if it were possible. You're thinking "single thread". What if this were a multi-threaded application? You'd never be sure which Collection would be available when your thread executed that method. Method calls should do one thing and one thing only, without side effects. %