Result: 55
negate() and immutable
negate() creates a new object, the negative of an existing BigInteger.
BigInteger value = new BigInteger( "38412946784" );
System.out.println( "Original: " + value );
value = value.negate(); // this creates a new object
// and puts its reference in value
System.out.println( "New: " + value );
BigIntegers are immutable.
You can't change the sign (or otherwise alter) a BigInteger object.
The above code starts with value pointing to a BigInteger object.
That object's negate() methods runs, creating a new object.
A reference to that object is placed in value.
The original object becomes garbage.
The program prints:
Original: 38412946784 New: -38412946784
Warning: often people misleadingly say that the first object has been converted to a negative. But in fact, a totally new object is created.
What is printed by the following?
BigInteger value = new BigInteger( "50" ); value = value.negate().negate(); System.out.println( "New: " + value );
How many objects are created by the three lines of code?
How many reference variables are there in this code?