Question

Which of the below options has the best performance while converting string to Boolean?

1. boolean value = new Boolean("true").booleanValue();
2. boolean value = Boolean.valueOf("true");
3. boolean value = Boolean.parseBoolean("true");

Answer 1

boolean value = new Boolean("true").booleanValue();

is the worst. It creates new Boolean objects all the time. BTW, booleanValue() is not necessary; unboxing will do it for you.

boolean value = Boolean.valueOf("true");

is much better. It uses a cached Boolean instance, but it performs unnecessary (although very cheap) unboxing.

boolean value = Boolean.parseBoolean("true");

is best. Nothing is wasted, it operates barely on primitives, and no memory allocations are involved. BTW, all of them delegate to (Sun/Oracle):

private static boolean toBoolean(String name) { 
  return ((name != null) && name.equalsIgnoreCase("true"));
}

If you are paranoid, you can create your own toBoolean(String name) not ignoring case— it is negligibly faster:

boolean value = "true".equals(yourString);