4.1. Introduction to Object-Oriented ProgrammingObject-oriented programming, or OOP for short, is the dominant programming paradigm these days, having replaced the "structured," procedural programming techniques that were developed in the 1970s.…
1.2. The Java "White Paper" BuzzwordsThe authors of Java have written an influential White Paper that explains their design goals and accomplishments. They also published a shorter summary that is organized along the following 11 buzzwords:1. Si…
4.7. PackagesJava allows you to group classes in a collection called a package. Packages are convenient for organizing your work and for separating your work from code libraries provided by others.The standard Java library is distributed over a numbe…
3.10. ArraysAn array is a data structure that stores a collection of values of the same type. You access each individual value through an integer index. For example, if a is an array of integers, then a[i] is the ith integer in the array.Declare an a…
3.8. Control FlowJava, like any programming language, supports both conditional statements and loops to determine control flow. We will start with the conditional statements, then move on to loops, to end with the somewhat cumbersome switch statement…
5.1. Classes, Superclasses, and SubclassesLet's return to the Employee class that we discussed in the previous chapter. Suppose (alas) you work for a company at which managers are treated differently from other employees. Managers are, of course, jus…
4.10. Class Design HintsWithout trying to be comprehensive or tedious, we want to end this chapter with some hints that will make your classes more acceptable in well-mannered OOP circles. 1. Always keep data private. This is first and foremost; doin…
4.6. Object ConstructionYou have seen how to write simple constructors that define the initial state of your objects. However, since object construction is so important, Java offers quite a variety of mechanisms for writing constructors. We go over t…
4.5. Method ParametersLet us review the computer science terms that describe how parameters can be passed to a method (or a function) in a programming language. The term call by value(值调用) means that the method gets just the value that the caller pro…
4.4. Static Fields and MethodsIn all sample programs that you have seen, the main method is tagged with the static modifier. We are now ready to discuss the meaning of this modifier.4.4.1. Static Fields(静态域)If you define a field as static, then there…
3.6. StringsConceptually, Java strings are sequences of Unicode characters(Java的字符串是一个Unicode序列). For example, the string "Java\u2122" consists of the five Unicode characters J, a, v, a, and ?. Java does not have a built-in string type(Java没有内置的…
3.5. OperatorsThe usual arithmetic operators +, -, *, / are used in Java for addition, subtraction, multiplication, and division. The / operator denotes integer division if both arguments are integers, and floating-point division otherwise. Integer r…
3.4. VariablesIn Java, every variable has a type. You declare a variable by placing the type first, followed by the name of the variable. Here are some examples: double salary; int vacationDays; long earthPopulation; boolean done; Notice the semicolo…
3.3. Data TypesJava is a strongly typed language(强类型语音). This means that every variable must have a declared type(每个变量都必须声明类型). There are eight primitive types in Java(Java有8种原始类型). Four of them are integer types; two are floatingpoint number types;…
Let’s look more closely at one of the simplest Java programs you can have—one that simply prints a message to console: public class FirstSample { public static void main(String[] args) { System.out.println("We will not use 'Hello, World!'"); } }…
今天重扫了corejava 14 并发的一章,在谈到volatile域代替synchronized 应用于并发更新时,看到如下内容,并发更新可用内部锁的方式但会带来阻塞问题,可用volatile域替代.个人发觉好像有哪里欠了点逻辑,似乎volatile域为什么能替代内部锁并没有讲明原因.秉承着疑惑对了一下原版. 果然在原版中多了这么一句解释: The compiler will insert the appropriate code to ensure that a change to the…
swift面向协议编程的根本原因在于值类型的存在:面向对象必须要有引用类型的支持: Protocol Oriented approach was introduced to resolve some issues in programming and it also differs in various scenarios when compared to Object-Oriented programming. So let’s dive into the topic. What is Pro…
今天起开始学习Java,学习用书为Core Java.之前有过C的经验.准备把自己学习这一本书时的各种想法,不易理解的,重要的都记录下来.希望以后回顾起来能温故知新吧.也希望自己能够坚持把自己学习这本书的整个过程记录下来. I want to put a ding in the universe. 基本术语: Object Oriented Programming——OOP——面向对象编程 Application Programming Interface——API——应用程序编程接…
class fun { public static void main(String[] args) { String str="java is an object oriented programming language"; String[] strs = str.split(" "); int sum = 0; for(int i=0;i<strs.length;i++) { sum += strs[i].length(); System.out.pri…
Difference between Vector and Arraylist is the most common Core Java Interview question you will come across in Collection . This question is mostly used as a start up question by the Interviewers before testing deep roots of the Collection .Vec…
This is a new series of sharing core Java interview question and answer on Finance domain and mostly on big Investment bank.Many of these Java interview questions are asked on JP Morgan, Morgan Stanley, Barclays or Goldman Sachs. Banks mostly asked c…
Java里面的String Conceptually, Java Strings are sequences of Unicode characters. Java里面的String都是Unicode字符串 Java does not have a built-in string type. java没有内建的字符串类型. Each quoted string is an instance of the String class. 每个引用的字符串都是一个String类的实例. 字符串是永恒的:…
We are sharing 25 java interview questions , these questions are frequently asked by the recruiters.Java questions can be asked from any core java topic . So we try our best to provide you the java interview questions and answers for experienced whic…
