Java object initialization and code block initialization sequence

"Test !!!!!!!!!!! "Demo19 = 7; System. out. println (" hello world! Execution sequence of the test code block! AAAAAAAAAAA "x = 1; y = 2; Demo19 (d_x, x = 13; System. out. println (" hello world! Test code block execution sequence! BBBBBBBBBBBB "Demo19 demo =" test code block: x = "+ demo. x + ", y =" + Demo19 demoOne = Demo19 (12, 45 "test code block: x =" + demoOne. x + ", y =" + "other orders remain unchanged! This is an important "" code block! "

 

Initialization of abstract classes:

B C "if the subclass is not an abstract class, you must implement the method of the parent class" "test the constructor of the abstract class! "String name =" What is your "D" subclass calls the constructor of the parent class "" If the abstract class has no abstract method, so there is no problem with inheritance. "=" abstract class !!!!! "" Classes do not support multi-level inheritance !!!!!!!!!!!!!!!! "