Java Interview Questions – Part 1

Collections API Which data structure is used when you have lots of add and remote operations? What is time complexity? LinkedList. The insertion, addition and removal operations of an item are faster in a LinkedList because there is no need to resize an array or update the index when an element is added to some arbitrary position […]

If/Else Cumleleri Icin Rule Tasarim Kalibi

Bugun, projemizde kullandigimiz Rule tasarim kalibi (Rule Design Pattern) anlatacagim. Bu yontemi zaman baskisi yuzunden ekibe kabul ettirmek zor oldu ama ortaya cikan sonuctan memnun kaldik. Umarim sizin de isinize yarar. Problem Spring Boot ile yazilan backend uygulamamizda farkli musteri tipleri icin farkli kurallarin uygulandigi bir fonksiyon vardi. Musteri tiplerine gore onyuze farkli bildirim mesajlarini […]

Java SE 8/11 Programmer II Exam Series: Internationalization and Localization

Introduction In this post, we will look at how to add internationalization and localization to the Java application. We will learn how to pick a locale, create and use properties files in different languages, and to format the numbers. Note that the localization is also a part of the Java SE 11 Programmer II Certification. […]

Item 42: Prefer lambdas to anonymous classes

Anonymous classes were adequate for the classic objected-oriented design patterns requiring function objects. Here’s a code snippet using an anonymous class. // Anonymous class instance as a function object – obsolete! Collections.sort(words, new Comparator<String>() { public int compare(String s1, String s2) { return, s2.length()); } }); Interfaces with a single abstract method are now […]

Item 15: Minimize the accessibility of classes and members

Encapsulation A well-designed component hides all its implementation details, cleanly separating its API from its implementation. Components then communicate only through their APIs and are oblivious to each others’ inner workings. This concept, known as information hiding or encapsulation, is a fundamental tenet of software design. The advantages of encapsulation are as follows: Speeds up […]

Class Initialization

Today, I will briefly mention about the class initialization. When we execute any java program (e.g.: java InitTest), Java Virtual Machine loads and link the class, execute initializers, and invokes the main class. Initialization process has some rules. Before we go into the details, spend a few minutes to figure out the output. class SuperClass { static { System.out.print(“0 […]