Infosys Oracle SQL and PLSQL Developer Interview Questions, Process, and Tips

Abstraction is the process of hiding complex implementation details and exposing only the necessary information.

• Abstraction helps in reducing complexity and increasing efficiency.

• It allows us to focus on the essential features of an object or system.

• Abstraction can be achieved through abstract classes, interfaces, and encapsulation.

• For example, a car can be abstracted as a vehicle with certain properties and methods.

• Ab...read more

Hiding implementation means keeping the internal details of a class or function hidden from the outside world.

• It is a fundamental principle of object-oriented programming.

• It helps in achieving encapsulation and abstraction.

• It prevents the user from accessing the internal workings of a class or function.

• Examples include private variables and methods in a class.

• It allows for easier maintenance and modification of code.

• It...read more

A closure is a function that has access to its outer function's variables, even after the outer function has returned.

• A closure is created when a function is defined inside another function.

• It allows for private variables and functions in JavaScript.

• Closures are used for data hiding, encapsulation, and creating modules.

• Example: function outer() { var x = 10; function inner() { console.log(x); } return inner; } var clos

Basic structure of an HTML page includes doctype declaration, html, head, and body tags.

• DOCTYPE declaration specifies the HTML version

• HTML tag wraps the entire content of the page

• Head tag contains meta information, title, and links to external resources

• Body tag contains the visible content of the page

Padding is the space inside an element, while margin is the space outside an element.

• Padding is used to create space between an element's content and its border.

• Margin is used to create space between an element's border and the adjacent elements.

• Padding is affected by the background color of the element, while margin is not.

• Padding can be set individually for each side of an element (top, right, bottom, left), while ma...read more

Box Model is a concept in CSS where every element is treated as a box with content, padding, border, and margin.

• Box Model consists of content, padding, border, and margin.

• Content is the actual content of the box.

• Padding is the space between the content and the border.

• Border is the line that goes around the padding and content.

• Margin is the space outside the border.

Directives in Angular are markers on DOM elements that tell Angular to attach a specified behavior to that element.

• There are three types of directives in Angular: Component, Structural, and Attribute.

• Component directives are used to create reusable UI components.

• Structural directives are used to change the structure of the DOM.

• Attribute directives are used to change the appearance or behavior of an element.

• Examples of ...read more

JIT compiles code at runtime while AOT compiles code before runtime.

• JIT stands for Just-In-Time compilation and compiles code at runtime.

• AOT stands for Ahead-Of-Time compilation and compiles code before runtime.

• JIT is used in Java Virtual Machine (JVM) while AOT is used in languages like C and C++.

• JIT can result in slower startup time but faster execution while AOT can result in faster startup time but slower execution...read more

Abstract class is a class that cannot be instantiated and is used as a base class for other classes.

• An abstract class can have abstract and non-abstract methods.

• Abstract methods have no implementation and must be implemented by the derived class.

• An abstract class can have constructors and fields.

• An abstract class can be used to define a common interface for a group of related classes.

• Example: Animal is an abstract clas...read more