🗒️ Answer
If you're looking to learn Java comprehensively, there are several excellent online courses available:
Udemy offers a variety of Java courses suitable for beginners to advanced learners, such as their Java Tutorial for Complete Beginners [3].
Coursera provides courses with certificates, including options to learn Java from industry experts [2].
MyGreatLearning offers a free Java programming course, focusing on hands-on learning from basics [4].
W3Schools provides a Java tutorial that covers the essentials and includes certification options [5].
Codecademy's Learn Java course allows you to build practical skills with interactive lessons and certifications [6].
Each platform caters to different learning styles and levels of expertise, ensuring you can find a course that suits your needs.
🌐 Sources
- udemy.com - Java Tutorial for Complete Beginners
- coursera.org - Best Java Courses Online with Certificates [2024]
- mygreatlearning.com - Free Java Programming Course with Certificate [2024]
- w3schools.com - Java Tutorial
- codecademy.com - Learn Java
Classes And Objects In Java
Classes, fields, methods, constructors, and objects are the building blocks of object-based Java applications. This Java tutorial teaches you how to declare classes, describe attributes via fields, describe behaviors via methods, initialize objects via constructors, and instantiate objects from classes and access their members. You'll also learn about setters and getters, method overloading, and setting access levels for fields, constructors, and methods.
What you'll learn in this Java tutorialDownload the source code for example applications in this tutorial. Created by Jeff Friesen.
How to declare a classA class is a template for manufacturing objects. You declare a class by specifying the class keyword followed by a non-reserved identifier that names it. A pair of matching open and close brace characters ({ and }) follow and delimit the class's body. This syntax appears below:
class identifier { // class body }By convention, the first letter of a class's name is uppercased and subsequent characters are lowercased (for example, Employee). If a name consists of multiple words, the first letter of each word is uppercased (such as SavingsAccount). This naming convention is called CamelCasing.
The following example declares a class named Book:
class Book { // class body }A class's body is populated with fields, methods, and constructors. Combining these language features into classes is known as encapsulation. This capability lets us program at a higher level of abstraction (classes and objects) rather than focusing separately on data structures and functionality.
Utility classesA class can be designed to have nothing to do with object manufacturing. Instead, it exists as a placeholder for class fields and/or class methods. Such a class is known as a utility class. An example of a utility class is the Java standard class library's Math class.
Multi-class applications and main()A Java application is implemented by one or more classes. Small applications can be accommodated by a single class, but larger applications often require multiple classes. In that case one of the classes is designated as the main class and contains the main() entry-point method. For example, Listing 1 presents an application built using three classes: A, B, and C; C is the main class.
Listing 1. A Java application with multiple classesclass A { } class B { } class C { public static void main(String[] args) { System.Out.Println("Application C entry point"); } }You could declare these three classes in a single source file, such as D.Java. You would then compile this source file as follows:
javac D.JavaThe compiler generates three class files: A.Class, B.Class, and C.Class. Run this application via the following command:
java CYou should observe the following output:
Application C entry pointAlternatively, you could declare each class in its own source file. By convention, the source file's name matches the class name. You would declare A in A.Java, for instance. You could then compile these source files separately:
javac A.Java javac B.Java javac C.JavaTo save time, you could compile all three source files at once by replacing the file name with an asterisk (but keep the .Java file extension):
javac *.JavaEither way, you would run the application via the following command:
java CWhen designing multi-class applications, you will designate one of these classes as the main class and locate the main() method in it. However, there is nothing to prevent you from declaring main() methods in the other classes, perhaps for testing purposes. This technique is shown in Listing 2.
Listing 2. Declaring more than one main() methodclass A { public static void main(String[] args) { System.Out.Println("Testing class A"); } } class B { public static void main(String[] args) { System.Out.Println("Testing class B"); } } class C { public static void main(String[] args) { System.Out.Println("Application C entry point"); } }After compiling the source code, you would execute the following commands to test the helper classes A and B, and to run the application class C:
java A java B java CYou would then observe the following lines of output, one line per java command:
Testing class A Testing class B Application C entry pointUsing fields to describe attributesA class models a real-world entity in terms of state (attributes). For example, a vehicle has a color and a checking account has a balance. A class can also include non-entity state. Regardless, state is stored in variables that are known as fields. A field declaration has the following syntax:
[static] type identifier [ = expression ] ;A field declaration optionally begins with keyword static (for a non-entity attribute) and continues with a type that's followed by a non-reserved identifier that names the field. The field can be explicitly initialized by specifying = followed by an expression with a compatible type. A semicolon terminates the declaration.
The following example declares a pair of fields in Book:
class Book { String title; int pubYear; // publication year }The title and pubYear field declarations are identical to the variable declarations I presented in Java 101: Elementary Java language features. These fields are known as instance fields because each object contains its own copy of them.
The title and pubYear fields store values for a specific book. However, you might want to store state that is independent of any particular book. For example, you might want to record the total number of Book objects created. Here's how you would do it:
class Book { // ... static int count; }This example declares a count integer field that stores the number of Book objects created. The declaration begins with the static keyword to indicate that there is only one copy of this field in memory. Each Book object can access this copy, and no object has its own copy. For this reason, count is known as a class field.
InitializationThe previous fields were not assigned values. When you don't explicitly initialize a field, it's implicitly initialized with all of its bits set to zero. You interpret this default value as false (for boolean), '\u0000' (for char), 0 (for int), 0L (for long), 0.0F (for float), 0.0 (for double), or null (for a reference type).
However, it is also possible to explicitly initialize a field when the field is declared. For example, you could specify static int count = 0; (which isn't necessary because count defaults to 0), String logfile = "log.Txt";, static int ID = 1;, or even double sinPIDiv2 = Math.Sin(Math.PI / 2);.
Although you can initialize an instance field through direct assignment, it's more common to perform this initialization in a constructor, which I'll demonstrate later. In contrast, a class field (especially a class constant) is typically initialized through direct assignment of an expression to the field.
Lifetime and scopeAn instance field is born when its object is created and dies when the object is garbage collected. A class field is born when the class is loaded and dies when the class is unloaded or when the application ends. This property is known as lifetime.
Instance and class fields are accessible from their declarations to the end of their declaring classes. Furthermore, they are accessible to external code in an object context only (for instance fields) or object and class contexts (for class fields) when given suitable access levels. This property is known as scope.
Up next: Using methods to describe behaviors
Web Development Classes, Certificates And Bootcamps In NYC
Maintaining a solid online presence is vital for institutions, businesses and individuals in almost every professional context. This means that having access to someone who knows the ins and outs of web development is key, since programming and running web pages that work is an essential aspect of almost every public-facing business or project. Learning how to develop and maintain web pages will teach you a collection of professional skills that are only becoming more and more important as time goes on. If you are looking to learn how to code and run websites, you should consider looking into one of the many excellent training centers and educational resources available in NYC.
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What is web development?Web development is a large tent that encompasses all of the processes of building and maintaining the technical side of websites. This includes writing the code that the web browsers use to display the website, building and interlinking the databases that store important information pertaining to the pages and ensuring that the pages and databases are secure. Broadly speaking, since web development covers so many different topics, it is generally broken up into three smaller subsets focusing on what aspects of the development process are handled.
Front end web developmentFront end web development refers to the aspects of web development pertaining to aspects of the page that are visible to the user and that they interact with while utilizing the page. For example, the visual representation of this text and the links directing readers to other pages, internal and external, are front end development issues. Front end web development tends to utilize HTML & CSS and JavaScript (as well as its assorted libraries) to add functionality and interactive elements to a web page, which are vital for providing end users with an experience that is conducive to your end goals (whether this is providing easier access to information, streamlining a virtual storefront or giving users access to contact information that they can use elsewhere).
Back end web developmentBack end web development covers the other half of the web development equation, handling the aspects of the web page that are not visible to the end user. This includes everything from password databases to automated forms and invoices being created after an item is purchased from a web store. Back end web development is less concerned with the look and feel of the page as they are with its internal functionality, so they will spend more time working with complex databases and languages like Python and SQL. Back end development also concerns itself with ensuring that the website continues to remain functional as changes are made to the front and that the website and its databases are protected from hostile threats.
Full stack web developmentUnsurprisingly, full stack web development is the process of building both the front end and back end for a website and ensuring that the two systems work well with one another. Full Stack Developers will either learn how to use several different programming languages to build end-user content and databases or they will specialize in a specific, versatile programming language (like JavaScript) that lets them handle all of the major aspects of web development using a single syntax. Full Stack Web Developers are often employed by companies to handle all aspects of the development and upkeep processes when they are launching or significantly modifying one of their websites.
Why learn web development?Learning web development is appealing because nothing in the present suggests that businesses and institutions are going to move away from focusing on their web presence. While hard figures are very difficult to come by, it is estimated that about 175 websites are launched every minute and there are over 4 billion active pages (with upwards of 50 billion on the high end of total pages). Web development isn’t going out of style anytime soon and learning how to develop websites is practical even if you aren’t planning to build a career out of it. Everyone from small business owners to artists can benefit from learning how to develop websites (though the emergence of platforms like WordPress make it easier than ever to utilize templates and creation wizards to make your own website).
Where To Find A C# Bootcamp Online In 2024
Though coding bootcamps cost less than traditional degree programs in most cases, they can still run thousands of dollars. Here’s what you should know about paying for bootcamps.
How Much Is a C# Bootcamp?Bootcamp costs vary significantly depending on factors such as program focus, reputability and faculty. Data collected by Forbes Advisor found that the median cost of a coding bootcamp was $9,500 as of November 2023.
Of the programs featured in this guide, one is free, and the other costs $9,800.
Upfront PaymentFor the lowest overall price, consider making an upfront payment. Providers often offer discounts to learners who can pay their full tuition cost at the outset of the program. Not all students can afford to make such a payment in one lump sum, however, making some other financing methods more manageable.
Pay in InstallmentsWith installments, you can spread out your tuition payments over time, giving you a bit more breathing room by breaking up your total cost into smaller payments. However, you’ll likely end up paying more over time with an installment plan than you would with an upfront payment.
Income Share Agreement (ISA)With an ISA, you can delay tuition payments until after you’ve graduated from your bootcamp and secured a job. On the flip side, you must agree to paying a set percentage of your income for a set period of time.
This method may sound appealing, but it’s worth digging into the details of an ISA before committing. Say you complete a $18,000 bootcamp and agree to a three-year, 8% ISA. After graduation, you land a job that pays $100,000 per year. You’d then have to pay $8,000 per year in tuition for a total of $24,000—significantly more than the initial tuition cost.
However, if you’re fortunate enough to find a role that pays a $250,000 salary, you’d be stuck paying 8% of that income—$20,000 per year—for three years, unless your ISA includes a payment cap. Even with a cap, you may still end up paying up to one-and-a-half times the actual tuition with this method.
Job GuaranteeSome bootcamps offer job guarantees. With this policy, you’re only liable to pay tuition if you land relevant employment within a specific span of time after completing the bootcamp.
A job guarantee may sound appealing, but like an ISA, you should always read the fine print before committing. Bootcamps often set strict requirements to qualify for a job guarantee, such as stipulating a certain number of job applications or networking events. They may also set restrictions on locations for jobs you can apply for.
Loans, Scholarships and Other AidUnlike formal degrees, bootcamps typically do not qualify for federal student aid. However, many providers partner with private creditors to offer loans with little or no interest for a set period. Some bootcamp providers offer scholarships as well.