转换/转换双精度为int？ （对象到基本类型）

Question

How do I convert/cast a Double object to an int ?

Double d = new Double(12.34);
int i = 12 //is what I'm looking for

If I had a double I would just use:

double z = 12.34;
int i = (int)z;

Note: I want it to truncate the Double (so 12.9 becomes 12) because I know that d actually was an integer that was converted to a Double. Ie I want to call (int) on a Double .

Answer 1

To perform this operation you need to call the intValue method on the Double object:

int i = d.intValue();

This method performs a cast, into an int value, on the double value wrapped within the Double object, d .

Note that it does not check for null before attempting this.

Answer 2

If you want to use a cast you can use

Double d = 12.34;
int i = (int) (double) d;

You can't cast from Double to int in one step.