Question

I was going through some code today and saw this:

    x.add(getResources().getString(R.string.none));
    x.add(getResources().getString(R.string.today));
    x.add(getResources().getString(R.string.tomorrow));
    ...

and so I thought, “that’s inefficient!” and started to change it to:

    Resources res = getResources();
    x.add(res.getString(R.string.none));
    x.add(res.getString(R.string.today));
    x.add(res.getString(R.string.tomorrow));
    ...

but then I stopped and wondered: Is the second section of code really more efficient or does it not really matter? Is the compiler going to generate the same byte code either way?

Answer 1

The compiler will not generate the same byte code, but if getResources() is a trivial method then the JIT-compiler may effectively run the same code at execution time.

Personally I prefer the second form on the grounds of it being cleaner and more readable rather than for performance reasons.