Is there any advantage to int i = array.length over just calling array.length twice?

Question

Is any benefit--small as it may be--of putting the length of an array into an int in this situation, or is simply calling array.length twice better? Or does compiler optimization make these approaches equivalent?

No int:

Vector<String> vs = new Vector<String>(a_o.length);
for(int i = 0; i < a_o.length; i++)  {
   vs.add(a_o[i]);
}

int:

int iLen = a_o.length;
Vector<String> vs = new Vector<String>(iLen);
for(int i = 0; i < iLen; i++)  {
   vs.add(a_o[i]);
}

score 5 · Answer 1 · edited May 23 '17 at 11:56

5

AFAIK, a decent compiler the compiler will do this optimization for you.
And even if not, the hit is minimal. You are probably going to suffer much more from using Vector. see Why is Java Vector class considered obsolete or deprecated?

edited May 23 '17 at 11:56

Community

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1

answered Dec 14 '13 at 19:38

Itay Karo

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Point taken about Vector. I'm considering changing it to ArrayList as mentioned there. Thank you. – aliteralmind Dec 14 '13 at 20:01

score 1 · Accepted Answer · answered Dec 14 '13 at 19:38

1

The compiler is smart, trust it. It'll optimize it.

Don't waste time on performance issues like this one, worry more about other things like data structures..

answered Dec 14 '13 at 19:38

Maroun

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Is there any advantage to int i = array.length over just calling array.length twice?

2 Answers2