Type conversion

Question 1

Data Type Conversion

Answer 1

• The process of converting one predefined
data type into another is called Type
Conversion.
• Java facilitates type conversion in 2 forms:
– Implicit Type Conversion (also known as
Promotion or Coercion)
– Explicit Type conversion or Type Casting

Question 2

Implicit Type conversion

Answer 2

Implicit Type Conversion
• This type of conversion is performed in Java
without the programmer’s intervention.
• It is generally applied in a mixed arithmetic
expression.
• All operands are converted to the largest data
type in the expression, in order to prevent
loss of data.
• It is also known as coercion and promotion.

Question 3

Explicit Type Conversion

Answer 3

• This is a user-defined conversion that forces an expression to
be of specific type. It is called Type Casting.
• This is normally done when a value of a larger data type is to
be assigned to a smaller data type.
• This is not done implicitly

Question 4

Potential conversion problems

Answer 4

Type Casting may pose the following problems:
– Conversion from float to integer may result in the loss of
fractional part(wherein the float is not rounded up).

– In the case of conversion from bigger integer to smaller integer
type, original value may be out of range for target type,
resulting in loss of information.

– In the case of conversion from bigger floating-point type to
smaller floating-point type, there will loss of
precision(significant figures) and original value may be out of
range for target type, thereby resulting in loss of information.

Question 5

Impossible Conversions

Answer 5

• Any primitive type to a Reference Type or any Reference to a
Primitive type 
• Null value to any primitive type
• Any primitive to Boolean
• Boolean to any primitive type