Everything is object
1. Java uses Reference to manipulate the object, and Reference is stored in the Stack and can exist independently; 2. Places where data is stored: A.Registers: The fastest way, the number is limited, and the compiler is assigned. Java is not stored here. B.Stack: Fast, efficient, but the data size and life cycle must be known. The REFERENCE and PRIMITIVE in Java are stored in this. C.HEAP: Flexible, slow. Java all object storage area. D.Static Storage: In a fixed location, the data can be accessed throughout the program. Some global variables in Java are stored here. E.Constant Storage: The constant value is usually placed directly in the program. F.non-Ram Storage: Data is independent of the program. Streamed Object and Persistent Object. 3. Biginteger and BigDecimal perform high precision. 4.java array will perform automatic initialization and boundary checks. When creating an object array, it is actually the reference to create an object. 5. The variable defined in the scope in the scope can only be used at the end of the scope. 6. Java actually passes the object when it passes the object is Reference. 7.Static Keywords: Static is stored in the class, will be saved in memory without instantiation. That is, class data and class methods. Relative is an example variable and an example method. STATIC has been saved in memory. STITIC data is only one of each class.
