Double.valueOf(s) vs. Double.parseDouble [duplicate]

Answer 1

If you just need the value (primitive) use parseDouble(String s) the cost is less. valueOf(String s) returns a Double class which wraps the primitive double value.

Answer 2

Because it is not the same. valueOf() creates a Double object which is often not needed. parseDouble() does not. With autoboxing it's valueOf(String) which is no longer needed, but is therefore backward compatibility.

Answer 3

parseDouble() returns a primitive double value. valueOf() returns an instance of the wrapper class Double. Before Java 5 introduced autoboxing, that was a very significant difference (and many would argue it still is).