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Part 10: Working with APIs in JavaScript

  Working with APIs in JavaScript Outline: 1. Introduction to APIs: 1.1 Definition of APIs: Explanation of what an API (Application Programming Interface) is. Understanding the role of APIs in web development. Types of APIs:  RESTful APIs, SOAP APIs, etc. 1.2 Importance of APIs in Web Development: How APIs facilitate communication between different software systems. Use cases of APIs in modern web development. Examples of popular APIs and their impact. 2. Making API Requests: 2.1 HTTP Methods: Overview of common HTTP methods: GET, POST, PUT, DELETE. Explanation of when to use each HTTP method. 2.2 Fetch API: Introduction to the Fetch API in JavaScript. Making simple GET requests with Fetch. Handling responses from Fetch requests. 2.3 Sending Data in API Requests: Using POST requests to send data to the server. Handling different types of data (JSON, form data) in API requests. 3. Handling API Responses: 3.1 Parsing JSON: Importance of JSON (JavaScript Object Notation) in API r...
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Q & A in Java basics Part-1

 

Q & A in Java basics Part-1

1.    What is Java?

Java is a widely used, high-level programming language known for its portability and ability to run on multiple platforms.

2.    What are the key features of Java?

Java is known for its platform independence, object-oriented nature, robustness, security, and automatic memory management.

3.    How do you define a class in Java?

To define a class in Java, you use the "class" keyword followed by the class name and curly braces containing class members

4.    What is a constructor in Java?

A constructor is a special method used to initialize the object's state when it is created. It has the same name as the class.

5.    How do you create an object in Java?

To create an object in Java, you use the "new" keyword followed by the constructor of the class as shown below:



6.    What is the difference between an instance variable and a class variable?

An instance variable is associated with an instance of a class and has a separate value for each object. A class variable, also known as a static variable, is shared among all objects of the class.

7.    Explain the main method in Java.

The main method is the entry point of a Java program. It has the signature as shown below:


8.    How do you print output to the console in Java?

You can use the System.out.println() method to print output to the console as shown below.


9.    What are Java data types?

Java has two categories of data types: primitive data types (e.g., int, double) and reference data types (e.g., String, Array).

10. Explain the difference between "==" and ".equals()" for comparing objects in Java.

"==" compares object references, while ".equals()" compares the content of objects. In most cases, you should use ".equals()" to compare objects for equality.

11. What is a package in Java?

A package is a collection of related classes and interfaces. It helps organize code and provides access control.

12. How do you import a package in Java?

You use the "import" statement followed by the package name at the top of your Java file to import a package as shown in the following figure:

13. What is method overloading in Java?

Method overloading allows you to have multiple methods with the same name in a class, but with different parameter lists.

14. What is method overriding in Java?

Method overriding occurs when a subclass provides a specific implementation for a method that is already defined in its superclass.

15. How do you handle exceptions in Java?

Exceptions are handled using try-catch blocks. The code that might raise an exception goes inside the "try" block, and the exception handling code goes inside the "catch" block.

16. What is the purpose of the "finally" block in exception handling?

The "finally" block is used to specify code that should be executed regardless of whether an exception occurs or not.


17. What is a static method in Java? 

      A static method belongs to the class rather than an instance of the class. It can be called using the class name.

18. How do you declare constants in Java?

     You can declare constants using the "final" keyword.


19. Explain the "this" keyword in Java.

The "this" keyword refers to the current instance of the class and is often used to distinguish between instance variables and method parameters with the same name.

20. What is method chaining in Java?

Method chaining is a technique where you call multiple methods on an object in a single line by returning the object from each method.



21. What is a static block in Java?

A static block is a block of code that runs when the class is loaded into memory, before the creation of any object.




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