Default Values for Data Types in Java

By: Baski Viewed: 153399 times  Printer Friendly Format    


It's not always necessary to assign a value when a field is declared. Fields that are declared but not initialized will be set to a resonable default by the compiler. Generally speaking, this default will be zero or null, depending on the data type. Relying on such default values, however, is generally considered bad programming style.

The following chart summarizes the default values for the above data types.

 

 

Data Type Default Value (for fields)
byte 0
short 0
int 0
long 0L
float 0.0f
double 0.0d
char '\u0000'
String (or any object)   null
boolean false

Local variables are slightly different; the compiler never assigns a default value to an uninitialized local variable. If you cannot initialize your local variable where it is declared, make sure to assign it a value before you attempt to use it. Accessing an uninitialized local variable will result in a compile-time error.



Most Viewed Articles (in Java )

Latest Articles (in Java)

Comment on this tutorial