Source: https://docs.google.com/presentation/d/1J3pc0cppixQEYul-UMnkKf4ukbmhTnkh/edit#slide=id.p1
Static/Non-Static
Memory
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Stack - The stack is for local variables and for maintaining a record of function calls. The stack grows from the top of memory down towards the heap.
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Heap - The heap is for dynamically allocated data items. The heap grows from the top of the static data area up as data items are allocated.
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Static Data - This is a block of reserved space in RAM for all the global and static variables from your program. Allocated once and lasts for duration of a program.
Static: Belongs to the class
- Class creates objects
- Constructor makes them unique (if needed)
- How to create a property that all objects share?
- You do not want to modify this property for each object. You may want to change it just once!
- Example: number of the cars sold, sound of the horn
Static: Shared properties and methods
Static variables: Common to all instances (One fixed memory location)
public static void main(String[] args) One special role for strings: Command line arguments
public class ArgsDemo {
/** Prints out the 0th command line argument. */
public static void main(String[] args) {
System.out.println(args[0]);
}
}