Default initial values for Java unassigned variables

In a Java program, any variable must be initialized before it can be used. When an object is created, the instance variable is assigned a value by the programmer-specified initialization value when allocating memory space, or the system is initialized by the following default values:

Data Type	Initial value
Byte	0
Short	0
Int	0
Long	0L
Char	' u0000 '
Float	0.0f
Double	0
Boolean	False
All reference types	Null

Note: A reference with a null value of "NULL" does not refer to any object. Attempting to use the object it references will cause an exception.

Default initial values for Java unassigned variables