Understanding Static Members
Definition of Static Members:
- Static members can be used independently of any instance of the class.
- They are declared with the static keyword.
- Methods and variables can be static.
Static Member Access:
- Do not require object instances to be accessed.
- Can be accessed using the class name followed by the dot operator (.).
- Access example: Timer.count = 10;
Classic Example:
- The main() method is static because it is called by the JVM when starting the program.
Static Variables:
- They are shared between all instances of the class.
- A single copy of the variable is available to all instances.
Code Example with Static Variables:
StaticDemo.java
- The static variable y is shared by all instances and its modification affects all of them.
Static Methods:
- Called using the class name, without having to create an object.
- Only other static methods can be called directly.
- Only static variables can directly access.
- Do not have this reference.
Code Example with Static Methods:
StaticMeth.java
Restrictions of Static Methods:
- Cannot access instance variables directly.
- Example error: A static method trying to access a common instance variable will result in a compilation error.
See StaticError.java
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