Unnecessary object creation...

Most of you might already know about this. I just found this out while working on my open source project JNeuralNet.

I had this situation:

loop
{
 Double d = someclass.compute();
}

When i ran the profiler. I noticed that the major portion of CPU was going into Double object creation. That's when i realized that its the classloader overload everytime the object is being created..so this is what i did:

//init variable...
Double d = 0.0;
loop
{
  d = someclass.compute();
}

This simple optimization reduced a lot of CPU overload! Also if u have situations such as:

loop
{
  Obj o = new Obj();
}

If feasible...try using:

Obj o = new Obj();
loop
{
  //use o...
  o.set(abc);
}

This approach is not always feasible...especially if you intend to use the reference of the object elsewhere, my point is, to reduce object creation wherever feasible.