Question from mock exam

[Punitha krishna]

Which assignments are legal?
Select all valid answers.
a. long test = 012;
b. float f = -412;
c. int other = (int)true;
d. double d = 0x12345678;
e. short s = 10;
The correct answers are a,b,d,e.
I don't understand how b and d are correct.

[Milind Deodhar]

b is correct because it is a int value and can be put in float without casting. (even if it is negative).
Second is correct, because I think double can hold the biggest value and no cast is required to put any primitive into double
(only cannot put boolean value)

[Punitha krishna]

Thanks It is clear now. I guess I didn't read the question properly.

[David Roberts]

You probably already know this but:
float f = -412; //Would Pass (int fits in float)
float f = -412.0; //Would fail (double doesn't fit in float)
float f = -412.0f; //Would pass (explicitly stating float)
float f = (float)-412.0; //Would pass (Cast)
- David

[Vladimir Kositsky]

Java allows conversion between integer values( byte, short, int, long) and floating point values( float, double).
Both of questions are examples of "automatic" widening conversion, when value of "narrower" type is converted into "wider" type.
Vice versa explicit casting needed.