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Java Keywords (Part V): Classes vs Interfaces

This is not a break in my Java Keyword series. This is a continuation of the series that focuses in two things. The primary goal is to explain what an interface is (which differentiates them from classes) and go over a few examples that illustrate why interfaces are not just needed, but essential for robust and reusable software solutions. Because of new improvements introduced with Java 8, I will also introduced the concept of default methods; although will do so in a separate article... A second part to this one. I feel doing that is necessary for keeping the scope of this article as narrow as possible for the sake of simplicity and clarity. Interestingly enough, how to use interfaces will also be covered in a separate article where I will be discussing the Object-Oriented concept of inheritance. In the new article, I will be emphasizing in the keywords extends, implements, and super. The Java keyword list has 18 keywords grayed out. This article will only cover the interface …

Java Keywords (Part IV): Classes and Objects

This is not a break in my Java Keyword series. This is a continuation of the series that focuses in two things. The first part will focus on the anatomy of a class, which I have covered (somewhat) already. The second part focuses in the concept of a class constructor. Lastly, and as a related topic to that second part is how to invoke class constructors and explains what happens when this occurs (which I have somewhat covered already). View this article as a way to tie loose ends before moving on to other topics. In the end, I will wrap up the keywords class and the new operator. Java keyword listabstractcontinuefornewswitchassertdefaultgoto*packagesynchronizedbooleandoifprivatethisbreakdoubleimplementsprotectedthrowbyteelseimportpublicthrowscaseenuminstanceofreturntransientcatchextendsintshorttrycharfinalinterfacestaticvoidclassfinallylongstrictfpvolatileconst*floatnativesuperwhile Keyword marked with an asterisk (*) are keywords that, although valid, are not used by programmer…

Java Keywords (Part III): Returning Values from Methods

I have covered 7 keywords so far in the "Java Keyword" series, plus the eight primitive data types in my "Data Types" blog. In this article, I will discuss the keywords return and void. But, in order to understand their usage, I must get into a bit deeper discussion of some fundamentals of computing. Java keyword listabstractcontinuefornewswitchassertdefaultgoto*packagesynchronizedbooleandoifprivatethisbreakdoubleimplementsprotectedthrowbyteelseimportpublicthrowscaseenuminstanceofreturntransientcatchextendsintshorttrycharfinalinterfacestaticvoidclassfinallylongstrictfpvolatileconst*floatnativesuperwhile Keyword marked with an asterisk (*) are keywords that, although valid, are not used by programmers. Although the list above is arranged in alphabetical order, I will go through them in a different order. Method return valuesreturn and void It makes sense to discuss these two keywords together. They are almost symbiotic in nature. In a method definition, void i…

Java Keywords (Part II): Modifiers

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I will continue to show the keyword list on subsequent articles. However, I will gray out the keywords previously discussed. Since the eight primitive data types were also previously discussed, I will gray out those as well. Keywords that were mentioned but not discussed, like package will remain listed until properly explained and illustrated. Java keyword listabstractcontinuefornewswitchassertdefaultgoto*packagesynchronizedbooleandoifprivatethisbreakdoubleimplementsprotectedthrowbyteelseimportpublicthrowscaseenuminstanceofreturntransientcatchextendsintshorttrycharfinalinterfacestaticvoidclassfinallylongstrictfpvolatileconst*floatnativesuperwhile Keyword marked with an asterisk (*) are keywords that, although valid, are not used by programmers. Although the list above is arranged in alphabetical order, I will go through them in a different order. Modifiers Aside from the already discussed access modifiers, there are four other modifier keywords in Java. These are: abstract, fina…

Java Keywords (Part I): Creating Classes

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I think it is important for every beginner-level developer to fully understand the proper usage of keywords of any language. I will write a multi-part series outlining all Java keywords (as of Java 8), providing an explanation regarding it usage (or multiple usages), and illustrate this with simple examples. So, without further ado, lets examine this topic. The Java language contains 50 keywords of which only 48 are used. The following is a list of all the keywords in the Java programming language. Java keyword listabstractcontinuefornewswitchassertdefaultgoto*packagesynchronizedbooleandoifprivatethisbreakdoubleimplementsprotectedthrowbyteelseimportpublicthrowscaseenuminstanceofreturntransientcatchextendsintshorttrycharfinalinterfacestaticvoidclassfinallylongstrictfpvolatileconst*floatnativesuperwhile Keyword marked with an asterisk (*) are keywords that, although valid, are not used by programmers. Although the list above is arranged in alphabetical order, I will go through them …

Data Types

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The meaning of data type in programming To properly define what is a data type in computer science, we must understand first what "type" means. After perusing the web for a definition, I found this: -A category of people or things having common characteristics. In computer science, in this case specifically for programming in Java, a data type is simply a categorization of things (objects) that have common characteristics. For illustration purposes, let us consider something we are all familiarized with: money. Since I am American, I am more familiarized with American currency. Therefore, I will use that for my first example. American currency comes in bills or banknotes (generally referred as paper currency) and in metallic form called coins. Using the definition of data types, the generic data type known as "American Currency" can be further classified as "Paper Currency" and "Coin". Why do this? Because, although all forms of American cur…