Fields
Fields are given a default value when an object is created.
The default value for int is 0.
* For double fields, the default is 0.0.
For String and other object types, the default value is null.
null¶
A special value in Java that means a variable has been initialized, but doesn't point to an actual object.
Practice Exercise¶
Fields are different than local variables (variables declared inside a method) in that local variables must be initialized before they're used.
Fields will always have a value because Java inserts default values.
Scope¶
A variable's scope defines where it can be used in code.
* Think of scope as the pair of curly braces { } where a variable is defined.
Variables are available to all { } nested inside the { } where they are defined.
* Local variables are defined inside a method, and available to an if statement's code block.
* Fields are defined outside any method definition, so they are available to methods.
Fields can be defined above, between, and below the method definitions, but are usually placed at the top of the file.
