JSONArray does not have constructor to allocate the specified initial capacity

[viveksacademia4git]

The collection class like ArrayList has the constructor that accepts the number as an input to "Constructs an empty list with the specified initial capacity."
The absence of this functionality in the JSONArray will not affect the performance of the smaller applications with a fairly limited number of iteration, but the huge applications that involve a large number of iterations will result in the performance trade-off because ArrayList grows or expands numerous times.

[johnjaylward]

You are right. If you have a collection you are converting to a JSONArray, this constructor does the trick: https://github.com/stleary/JSON-java/blob/master/JSONArray.java#L171

However, if you are building up from scratch using an input where you can guess the size but not know an exact size, we don't expose a way to do that.

We have a code reorganization going on in PR #515, but a PR to support this should be pretty straightforward.

[stleary]

No objection to a pull request for this issue.

[viveksacademia4git]

Should I make changes?

[stleary]

Yes, please go ahead.

[viveksacademia4git]

Thank you @stleary.

[viveksacademia4git]

@johnjaylward and @stleary If we implement this constructor then I suppose that we also have to create a method to trim the size of the private ArrayList, like trimToSize(). So the final class will have these added components:

• Constructor - JSONArray(int)
• Method - Trims the size of private ArrayList

What do you think, is it feasible?

[viveksacademia4git]

I did not know that JSON-Java-unit-test existed for the purpose of unit testing, I will pull this branch.

[stleary]

@viveksacademia4git You have a reasonable use case for the constructor. What is your use case for the method?

[viveksacademia4git]

@stleary I do not have any practical use case as of now, but it occurred to me while working: what if someone has a use case which involves trimming the capacity of the underlying data structure.

But as I said before, "is it feasible" at this moment to create this method. Or we could introduce this kind of method if someone has a genuine and practical use case, and creates an issue requesting this functionality.

[stleary]

Recommend that you just add the constructor for now.

[viveksacademia4git]

Cool!

[viveksacademia4git]

@stleary I wasn't able to do the pull request that is why I preferred the fork option.
Please check these commits forked from JSON-Java and JSON-Java-unit-test

• Constructor implementation, Development for stleary#516 completed commit, Fork JSON-Java
• Test for Constructor implementation, Test for JSONArray(int) constructor code, Fork JSON-Java-unit-test

[viveksacademia4git]

I wasn't able to run the gradle test command but I executed the JUnit Test in Eclipse for the created test