java object oriented programming interview questions

Experiment Report and blog post situation.Experimental report not submitted by: Cao Cheng Cheng Deng Miaomiang Mitch ren red strong Wang Ruiqiang Zhang Budan knife Jeffan (has been granted extension until November 10)Blog not written by: dai Miaomiao Zhang aravind Novi Zassi goyangsomba Li Xianglong Mau ren red strong Wang Ruiqiang Ma Lun Mitch Mao ProvencaleAccording to the experimental work, the students generally reflect the four, the fifth experiment is more difficult, most students can n

on.A cat class inherits the animal class. Notice that there is an import in front of the class that imports the animal's package. As follows: Package Com.abc.one; Import Com.abc.two.Animal; Public class extends Animal { static{ System.out.println ("A cat"); } Public Static void Main (string[] args) { new Cat (); Cat.mathod (); }}Animal type: Package Com.abc.two; Public class Animal { publicstaticvoid main (string[] args) { System.out.println

extends Superclass{public void PrintA () {System.out.println ("Sub-class printing function");}}public class test2{public static void Main (String args[]){Superclass S1=new subclass ();S1.printa ();}}The methods in the subclass are executed at this time.Overloads of the method:That is, when a class has more than one method with the same name, and the parameters of these methods are not the same, the method is executed when the method is used, and that parameter matches the corresponding method.I

experience Can be designed according to the requirements of the Code, do not waste energy on the code you want; The design of the code to consider the problem more comprehensive, not easy to miss out important links; Psp: Steps Time Consuming/min Percent/% Demand analysis 10 9 Design 20 18 Code implementation 30 27 Test 20 28 Analysis Sum

by: Gao Shuping Gao Junmei Fong Mau Wang Ruiqiang Zong Peng Li Xianglong Ma Lun Mitch Mao ProvencaleCompared to the previous study summary can be found that there are students each time will appear in the list, their learning attitude is extremely not serious, very irresponsible to themselves. Some students copy and paste their homework, blog summary perfunctory. Hope that the students warning!According to the experimental work, found that students generally reflect the nineth experiment is mor

Experiment Report of Java object-oriented programming Initial mastery of UML modeling Familiarity with S.O.L.I.D principles Initial mastery of UML modeling Understanding Design PatternsLab Submission point 1: Unit Test(1) Three kinds of code伪代码It is an algorithm description language, with clea

using a range of outliers. When an object becomes unreachable, it can be reclaimed by the garbage collector.8. The System.GC () or RUNTIME.GC () method is the only mechanism for programmers to communicate with the JVM's garbage collector, but executing the GC () method does not guarantee that the garbage collector performs garbage collection immediately, only prompting the garbage collector to reclaim useless objects as soon as possible.9. The finali

life cycle of an object The creation of the object must have a constructor method. Create object sub-declaration and allocate memory two steps. Memory conditions:Defines a variable that does not allocate memory, and only assigns the initial value to allocate memory.Defines a local variable and assigns an initial value, at which time there is me

of the parent class, which improves the reusability of the Code;later extension and maintenance, just add the corresponding subclass. other points of knowledge related to:Super Keyword: An object that represents the parent class, invokes the properties of the parent class ,methods, construction methods. abstract Keyword: abstraction, adornment class, adornment method. static keyword: statically, decorated property, method, code block,Inner classFinal

. Inheritance Benefits: Subclasses share the code of the parent class, improving the reusability of the Code; Code later extension and maintenance, just add the corresponding subclass. Other knowledge points involved: Super Keyword: An object representing the parent class, calling the parent class's properties, methods, and construction methods. abstract Keyword: abstract, decorated class, cosmetic method. static keyword: static, cosmeti

the code of the parent class, which improves the reusability of the Code; later extension and maintenance, just add the corresponding subclass. related to other knowledge points: Super Keyword: An object representing the parent class, calling the properties of the parent class, method, construction method. abstract Keywords: abstract, decorated class, cosmetic method. static keyword: static, Decorated property, method, code block, inner c

: Subclasses share the code of the parent class, which improves the reusability of the Code;later extension and maintenance, just add the corresponding subclass. other points of knowledge related to:Super Keyword: An object that represents the parent class, calling the parent class's properties, methods, and construction methods. abstract Keyword: abstraction, adornment class, adornment method. static keyword: statically, decorated property, method, c

20145311 experiment Two "Java Object-oriented programming" program design process experiment contentDesign and implement the plural class Complex using unit Test and TDD methodWrite code:1, the first design to realize the plural class Complex, the plural class Complex method design has: the plural class definition, the

, dependency inversion principle) (2) Pattern and Design pattern (3) Example of design patternIV) Exercise 1 using TDD to design the complex to implement the plural class.2. Experiment report to count your PSPTime Steps Time Consuming percentage Demand analysis 20 minutes 13.3% Design About 10 minutes. 6.67% Code implementation 1 hours 30 minutes or so 60% Test 30

; NBSP; NBSP; 11th week NBSP; NBSP; NBSP; NBSP; 13th week NBSP; NBSP; NBSP; NBSP; 14th week NBSP; NBSP; NBSP; NBSP; 15th week NBSP; NBSP; NBSP; NBSP; 16th week NBSP; NBSP; NBSP; NBSP; 17th week

construct methods in this class that have and allow only the first line of code in the method body to appearThe variable defined in the normal (instance) method must be appended with the initial value (not giving you no error when you do not call it)If you don't give an error when you callstatic modifierYou can modify----static variable (class variable) class name on a variable. Static variable nameCan be decorated on a normal method--static method (class method) class name. static method NameC

; int fib[]=new int[m]; for(n=0;n The code has the following problems: The class name does not match the naming convention; Sentence structure is not easy to read Experiment Three, agile development and XP practice-3 experimental content Refer to Http://www.cnblogs.com/rocedu/p/6683948.html to complete the learning of Java cryptography related content in pairs, combining refactoring, git,

overloadsMethod overrides and method overloads have the following same points: Requires a method with the same name. Can be used between abstract methods and non-abstract methods. Method overrides and method overloads have the following different points: Method overrides require that parameter signatures must be consistent, and method overloading requires parameter signatures to be inconsistent. Method overrides require that the return type be consistent, and the

error; implements polymorphic conditions: the existence of an inheritance, the method of overriding the parent class by a subclass, the reference variable of the parent class to the child class object; NBSP; Subclass is converted to a parent class (a reference to a parent class is directed to a subclass object), called an upward transformation; A class inherit

!The memory allocation diagram for this code is as follows:This is the difference between a class variable and an instance variable!Objects are created through classes, so you need to load the appropriate classes when you create the objects. A class can create multiple objects, and each object has its own entity.Difference:1. Class variables (such as classer above) allocate memory when the class loads, instance variables (such as age above) are alloca