10+ Juspay Technologies Interview Questions and Answers

The output will be 'bye'.

• The code defines a struct 's1Struct' with a property 'abc' initialized to 'Hello'.

• It also has a method 'change()' that changes the value of 'abc' to 'bye'.

• An instance 'a' of 's1Struct' is created and its 'change()' method is called.

• Finally, the value of 'abc' in the instance 'a' is printed, which will be 'bye'.

Liskov Substitution Principle focuses on inheritance while Interface Segregation Principle focuses on interfaces.

• Liskov Substitution Principle states that objects of a superclass should be replaceable with objects of its subclasses without affecting the program's correctness.

• Interface Segregation Principle states that a client should not be forced to implement interfaces they do not use.

• Liskov Substitution Principle is related to inheritance hierarchy, while Interface Segrega...read more

The time complexity for finding the longest common prefix in an array of strings is O(n*m), where n is the number of strings and m is the length of the longest string.

• Iterate through the characters of the first string and compare them with the corresponding characters of the other strings.

• The worst-case scenario is when all strings have the same prefix, resulting in O(n*m) time complexity.

• Example: For strings ['apple', 'app', 'apricot'], the longest common prefix is 'ap'.

Structs are value types, leading to better performance and memory management in SwiftUI.

• Structs are value types, meaning they are copied when passed around, leading to better performance compared to reference types like classes.

• Structs are immutable by default, making it easier to reason about the state of your app and preventing unexpected changes.

• Structs are more lightweight than classes, which can lead to better memory management in SwiftUI applications.

• Structs are preferr...read more

SOLID principles are a set of five design principles in object-oriented programming to make software more maintainable, flexible, and scalable.

• Single Responsibility Principle (SRP) - A class should have only one reason to change.

• Open/Closed Principle (OCP) - Software entities should be open for extension but closed for modification.

• Liskov Substitution Principle (LSP) - Objects of a superclass should be replaceable with objects of its subclasses without affecting the functiona...read more

Automatic Reference Counting (ARC) is a memory management feature in iOS development that automatically manages memory by keeping track of references to objects.

• ARC automatically adds and removes retain/release calls to manage memory for objects.

• It helps prevent memory leaks by deallocating objects when they are no longer needed.

• ARC is the default memory management model in Swift and Objective-C.

• Example: var myObject = MyObject() // ARC automatically retains myObject

• Example: ...read more

A retain cycle in programming occurs when two objects hold a strong reference to each other, preventing them from being deallocated.

• Retain cycles can lead to memory leaks in iOS development.

• To break a retain cycle, one of the objects involved needs to have a weak reference to the other.

• An example of a retain cycle is when a parent object holds a strong reference to a child object, and the child object holds a strong reference back to the parent.

Handle reference cycles by using weak or unowned references to break the strong reference cycle.

• Use weak or unowned references to break strong reference cycles

• Weak references do not keep a strong hold on the instance they refer to

• Unowned references assume that the instance they refer to will never be nil

Computed properties are properties in Swift that do not store a value directly, but instead provide a getter and an optional setter to retrieve and set their value.

• Computed properties do not have a backing store like stored properties.

• They are used to calculate a value on-the-fly based on other properties or data.

• Example: calculating the area of a square based on its side length.

The mutating keyword is used in Swift to indicate that a method is allowed to modify the properties of a value type.

• Used in Swift with value types like structs and enums to allow methods to modify their properties

• Prevents compilation error when attempting to modify properties of a value type within a method

• Example: mutating func updateValue(newValue: Int) { self.value = newValue }

I used Combine to handle asynchronous events and data streams in my iOS app development.

• Used Combine to manage network requests and responses

• Implemented Combine to handle user input and UI updates

• Utilized Combine to combine multiple data streams and perform operations on them

Closures are functions that have access to variables from their containing scope even after the scope has closed.

• Closures allow functions to access variables outside of their scope

• They 'close over' their surrounding scope, retaining access to variables even after the scope has finished executing

• Closures are commonly used in JavaScript for callbacks and event handlers

Event loop is a mechanism in programming that allows for asynchronous execution of code by continuously checking for and handling events.

• Event loop is commonly used in JavaScript to handle asynchronous operations.

• It allows for non-blocking I/O operations by delegating tasks to the operating system.

• Event loop continuously checks the event queue for new events and executes them in a sequential manner.

• Example: In Node.js, the event loop allows for handling multiple requests conc...read more

Optimize website performance by implementing caching, minimizing HTTP requests, and optimizing images.

• Implement browser caching to reduce load times for returning visitors

• Minimize HTTP requests by combining CSS and JavaScript files

• Optimize images by compressing them and using the correct file format

• Use a content delivery network (CDN) to distribute content closer to users

• Enable Gzip compression to reduce file sizes transferred over the network