Xceller It Services Interview Questions and Answers

Threadlevel data page and clipboard are both storage areas in Pega platform, but with different scopes.

• Threadlevel data page is a storage area that is specific to a single thread of execution.

• Clipboard is a storage area that is shared across threads and is used to store data that needs to be accessed across multiple requests.

• Threadlevel data page is created and destroyed with the thread, while clipboard persists across requests.

• Threadlevel data page is used for temporary stor...read more

Declare expression is a rule that defines a value or a property in Pega Platform.

• Declare expressions are used to calculate values that are used in decision-making.

• They can be configured in the Declare Expression rule form.

• They can reference properties, functions, and other declare expressions.

• They can be used in data transforms, activities, and other rules.

• Examples include calculating a customer's age based on their birthdate, or determining a product's price based on its fea...read more

Stored procedures are precompiled SQL codes that can be executed multiple times, while functions return a single value.

• Stored procedures can modify database tables, while functions cannot.

• Functions can be used in SQL statements, while stored procedures cannot.

• Stored procedures can have input and output parameters, while functions can only have input parameters.

• Functions can be called from within stored procedures, but stored procedures cannot be called from within functions.

State and props are two important concepts in React for managing data and passing data between components.

• State is used to store and manage data within a component. It is mutable and can be updated using setState() method.

• Props (short for properties) are used to pass data from parent components to child components. Props are immutable.

• State is internal to a component, while props are external and passed down from parent components.

• Example: State can be used to store form inpu...read more

Hooks in ReactJS are functions that let you use state and other React features without writing a class.

• Hooks were introduced in React 16.8 to allow functional components to have state and lifecycle methods.

• Some commonly used hooks are useState, useEffect, useContext, and useRef.

• Hooks can be used to manage component state, perform side effects, and access context in functional components.

• Example: useState hook allows you to add state to a functional component like a class comp...read more

Components in React are reusable, independent pieces of code that manage their own state and can be composed together to build complex UIs.

• Components are the building blocks of a React application

• They can be either functional components or class components

• Components can have their own state and lifecycle methods

• Components can be reused and composed together to create complex UIs

• Example:

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Components are reusable and independent parts of a software system that perform specific functions.

• Components are modular and can be easily integrated into different parts of a software system.

• They help in organizing code and promoting reusability.

• Examples include buttons, input fields, and dropdown menus in a user interface.