Different result with same if / else condition [duplicate]

This question already has an answer here:

• Why does the ternary operator unexpectedly cast integers? 2 answers

I always thought that this:

Object o1 = true ? new Integer(1) : new Double(2.0);

is the same as doing this:

Object o2;
if (true)
    o2 = new Integer(1);
else
    o2 = new Double(2.0);

But as output I got 1.0 for the first example and 1 for the second one.

Why they give me different results? And why I've got a Double result in the first place?