#Java_Interview_Question
👉Rules for #Constructors
■ Constructors can use any access modifier, including private. (A private constructor means only code within the class itself can instantiate an object of that type, so if the private constructor class wants to allow an instance of the class to be used, the class must provide a static method or variable that allows access to an instance created from within the class.)
■ The constructor name must match the name of the class.
■ Constructors must not have a return type.
■ It's legal (but stupid) to have a method with the same name as the class, but that doesn't make it a constructor. If you see a return type, it's a method rather than a constructor. In fact, you could have both a method and a constructor with the same name—the name of the class—in the same class, and that's not a problem for Java. Be careful not to mistake a method for a constructor—be sure to look for a return type.
■ If you don't type a constructor into your class code, a default constructor will be automatically generated by the compiler.
■ The default constructor is ALWAYS a no-arg constructor.
■ If you want a no-arg constructor and you've typed any other constructor(s) into your class code, the compiler won't provide the no-arg constructor (or any other constructor) for you. In other words, if you've typed in a constructor with arguments, you won't have a no-arg constructor unless you type it in yourself!
■ Every constructor has, as its first statement, either a call to an overloaded constructor (this()) or a call to the superclass constructor (super()), although remember that this call can be inserted by the compiler.
■ If you do type in a constructor (as opposed to relying on the compiler-gener- ated default constructor), and you do not type in the call to super() or a call to this(), the compiler will insert a no-arg call to super() for you, as the very first statement in the constructor.
■ A call to super() can be either a no-arg call or can include arguments passed to the super constructor.
■ A no-arg constructor is not necessarily the default (i.e., compiler-supplied) constructor, although the default constructor is always a no-arg constructor. The default constructor is the one the compiler provides! While the default constructor is always a no-arg constructor, you're free to put in your own no- arg constructor.
■ You cannot make a call to an instance method, or access an instance variable, until after the super constructor runs.
■ Only static variables and methods can be accessed as part of the call to super() or this().
■ Abstract classes have constructors, and those constructors are always called when a concrete subclass is instantiated.
■ Interfaces do not have constructors. Interfaces are not part of an object's inheritance tree.
■ The only way a constructor can be invoked is from within another constructor.
@javaCode☕️
👉Rules for #Constructors
■ Constructors can use any access modifier, including private. (A private constructor means only code within the class itself can instantiate an object of that type, so if the private constructor class wants to allow an instance of the class to be used, the class must provide a static method or variable that allows access to an instance created from within the class.)
■ The constructor name must match the name of the class.
■ Constructors must not have a return type.
■ It's legal (but stupid) to have a method with the same name as the class, but that doesn't make it a constructor. If you see a return type, it's a method rather than a constructor. In fact, you could have both a method and a constructor with the same name—the name of the class—in the same class, and that's not a problem for Java. Be careful not to mistake a method for a constructor—be sure to look for a return type.
■ If you don't type a constructor into your class code, a default constructor will be automatically generated by the compiler.
■ The default constructor is ALWAYS a no-arg constructor.
■ If you want a no-arg constructor and you've typed any other constructor(s) into your class code, the compiler won't provide the no-arg constructor (or any other constructor) for you. In other words, if you've typed in a constructor with arguments, you won't have a no-arg constructor unless you type it in yourself!
■ Every constructor has, as its first statement, either a call to an overloaded constructor (this()) or a call to the superclass constructor (super()), although remember that this call can be inserted by the compiler.
■ If you do type in a constructor (as opposed to relying on the compiler-gener- ated default constructor), and you do not type in the call to super() or a call to this(), the compiler will insert a no-arg call to super() for you, as the very first statement in the constructor.
■ A call to super() can be either a no-arg call or can include arguments passed to the super constructor.
■ A no-arg constructor is not necessarily the default (i.e., compiler-supplied) constructor, although the default constructor is always a no-arg constructor. The default constructor is the one the compiler provides! While the default constructor is always a no-arg constructor, you're free to put in your own no- arg constructor.
■ You cannot make a call to an instance method, or access an instance variable, until after the super constructor runs.
■ Only static variables and methods can be accessed as part of the call to super() or this().
■ Abstract classes have constructors, and those constructors are always called when a concrete subclass is instantiated.
■ Interfaces do not have constructors. Interfaces are not part of an object's inheritance tree.
■ The only way a constructor can be invoked is from within another constructor.
@javaCode☕️
#agile_manifesto
🔸Manifesto for Agile Software Development
We are uncovering better ways of developing software by doing it and helping others do it.
Through this work we have come to value:
1️⃣Individuals and interactions over processes and tools
2️⃣Working software over comprehensive documentation
3️⃣Customer collaboration over contract negotiation
4️⃣Responding to change over following a plan
That is, while there is value in the items on the right 👉️,
we value the items on the left 👈more.
@javaCode☕️
🔸Manifesto for Agile Software Development
We are uncovering better ways of developing software by doing it and helping others do it.
Through this work we have come to value:
1️⃣Individuals and interactions over processes and tools
2️⃣Working software over comprehensive documentation
3️⃣Customer collaboration over contract negotiation
4️⃣Responding to change over following a plan
That is, while there is value in the items on the right 👉️,
we value the items on the left 👈more.
@javaCode☕️
✅Principles behind the Agile Manifesto
We follow these principles:
1️⃣Our highest priority is to satisfy the customer through early and continuous delivery of valuable software.
2️⃣Welcome changing requirements, even late in development. Agile processes harness change for the customer's competitive advantage.
3️⃣Deliver working software frequently, from a couple of weeks to a couple of months, with a preference to the shorter timescale.
4️⃣Business people and developers must work together daily throughout the project.
5️⃣Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done.
6️⃣The most efficient and effective method of conveying information to and within a development team is face-to-face conversation.
7️⃣Working software is the primary measure of progress.
8️⃣Agile processes promote sustainable development. The sponsors, developers, and users should be able to maintain a constant pace indefinitely.
9️⃣Continuous attention to technical excellence and good design enhances agility.
🔟Simplicity--the art of maximizing the amount of work not done--is essential.
1️⃣1️⃣The best architectures, requirements, and designs emerge from self-organizing teams.
1️⃣2️⃣At regular intervals, the team reflects on how to become more effective, then tunes and adjusts its behavior accordingly.
@javaCode☕️
We follow these principles:
1️⃣Our highest priority is to satisfy the customer through early and continuous delivery of valuable software.
2️⃣Welcome changing requirements, even late in development. Agile processes harness change for the customer's competitive advantage.
3️⃣Deliver working software frequently, from a couple of weeks to a couple of months, with a preference to the shorter timescale.
4️⃣Business people and developers must work together daily throughout the project.
5️⃣Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done.
6️⃣The most efficient and effective method of conveying information to and within a development team is face-to-face conversation.
7️⃣Working software is the primary measure of progress.
8️⃣Agile processes promote sustainable development. The sponsors, developers, and users should be able to maintain a constant pace indefinitely.
9️⃣Continuous attention to technical excellence and good design enhances agility.
🔟Simplicity--the art of maximizing the amount of work not done--is essential.
1️⃣1️⃣The best architectures, requirements, and designs emerge from self-organizing teams.
1️⃣2️⃣At regular intervals, the team reflects on how to become more effective, then tunes and adjusts its behavior accordingly.
@javaCode☕️
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#JSON or JavaScript Object Notation is a lightweight text-based open standard designed for human-readable data interchange. The JSON format was originally specified by Douglas Crockford, and is described in RFC 4627. The official Internet media type for JSON is application/json. The JSON filename extension is .json. This tutorial will help you understand JSON and its use within various programming languages such as PHP, PERL, Python, Ruby, Java, etc.
@javaCode☕️
@javaCode☕️
➡️Uses of #JSON
1️⃣It is used while writing JavaScript based applications that includes browser extensions and websites.
2️⃣JSON format is used for serializing and transmitting structured data over network connection.
3️⃣It is primarily used to transmit data between a server and web applications.
4️⃣Web services and APIs use JSON format to provide public data.
5️⃣It can be used with modern programming languages.
@javaCode☕️
1️⃣It is used while writing JavaScript based applications that includes browser extensions and websites.
2️⃣JSON format is used for serializing and transmitting structured data over network connection.
3️⃣It is primarily used to transmit data between a server and web applications.
4️⃣Web services and APIs use JSON format to provide public data.
5️⃣It can be used with modern programming languages.
@javaCode☕️
Why MicroServices Architecture?
https://www.linkedin.com/pulse/microservices-%DA%86%D8%B1%D8%A7-ali-sharifi
author: @alisharifi01
@javaCode☕️
https://www.linkedin.com/pulse/microservices-%DA%86%D8%B1%D8%A7-ali-sharifi
author: @alisharifi01
@javaCode☕️
https://medium.com/@yazidaqel/quarkus-vertx-a-powerfull-combination-part-1-introduction-b039b911686
@javaCode☕️
@javaCode☕️
Medium
Quarkus & Vertx, a powerfull combination — Part 1 Introduction
Once you start thinking about microservices you will surely think of how those microservices will scale how they will communicate, what…
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Java_Performance_In_Depth_Advice_for_Tuning_and_Programming_Java.pdf
10.1 MB
#Java ☕️
#Book 📚📕
Coding and testing are generally considered separate areas of expertise. In this practical book, Java expert Scott Oaks takes the approach that anyone who works with Java should be adept at understanding how code behaves in the Java Virtual Machine—including the tunings likely to help performance. This updated second edition helps you gain in-depth knowledge of Java application performance using both the JVM and the Java platform.
@javaCode☕️
#Book 📚📕
Coding and testing are generally considered separate areas of expertise. In this practical book, Java expert Scott Oaks takes the approach that anyone who works with Java should be adept at understanding how code behaves in the Java Virtual Machine—including the tunings likely to help performance. This updated second edition helps you gain in-depth knowledge of Java application performance using both the JVM and the Java platform.
@javaCode☕️
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