You are implementing a method named Calculate that performs conversions between value types and reference types. The following code segment implements the method. (Line numbers are included for reference only.)
You need to ensure that the application does not throw exceptions on invalid conversions.
Which code segment should you insert at line 04?
To ensure that the application does not throw exceptions on invalid conversions, the correct code segment to insert at line 04 is: int balance = (int) (float) amountRef;. The initial conversion (float) amountRef takes the object amountRef and unboxes it back to a float, which is its original type. Then (int) casts the float to an int, ensuring that the final conversion is valid. Simply casting amountRef directly to an int, as in options B and C, would result in a runtime exception because amountRef is originally a float boxed inside an object. Option D is incorrect because amountRef is of type float, not double.
correct , (float) amountRef convert object to float (int) (float) amountRef convert (float) amountRef to int , this way we make sure that code does not throw exception by directly casting amountRef to int , B false
A is correct answer
A. int balance = (int) (float)amountRef;
A is correct
int balance = (int)amountRef; doesn't show compile time error, why is that?
It does throw an invallid cast exception at runtime
A: (float) unboxes the float from object, (int) casts the float to int