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In Swift, we can use the map() method to the dictionary to apply a transformation to the values of the dictionary. This method returns a newly created object with the same keys as the original dictionary but with the values transformed by the mapping function. Example 1: Transforming Values with a Closure In the following example, we are performing the multiplication on each value in the dictionary using the mapValues() function. We pass a closure that takes an argument. In the resulting dictionary, you can see that each value has been doubled. import Foundation let inputDictionary = [1: 2, 3: ... Read More
There is no single "best" practice for naming Swift files that add extensions to existing objects, but here are some commonly used conventions − Object Prefix Followed by Functionality String+Utilities.swift − adds utility functions to the String class Array+Sorting.swift − adds sorting functions to the Array class UIColor+Extensions.swift − adds color-related functions to the UIColor class Functionality Prefix Followed by Object CustomView+Animation.swift − adds animation functionality to a custom view class called CustomView JSONEncoder+CustomEncoding.swift − adds custom encoding and decoding functionality to the JSONEncoder class UICollectionViewLayout+Extensions.swift − adds layout-related functions to the UICollectionViewLayout class Descriptive Naming ... Read More
Caching is a technique to improve a computer's performance by storing frequently accessed data in a cache. The cache is a high-speed storage area in a computer. In this, data can be quickly retrieved from the cache rather than from slower main memory or disc storage whenever needed. Caching can be accomplished in a number of ways. This includes the use of a hash table, an array, or a linked list. In this article, we will explore the LRU Cache implementation using Double Linked Lists in detail. What is LRU Cache implementation? The Least Recently Used (LRU) algorithm is a ... Read More
Introduction In computer operating systems, the LRU (Least Recently Used) approximation algorithm, commonly called the Second Chance algorithm, is a page replacement algorithm. It is based on the principle that pages that haven't been used in a while are more likely to be replaced than pages that have. In this article, we will discuss the details, advantages, and disadvantages of this article. LRU Approximation Algorithm To keep track of which pages are currently in memory, the LRU approximation algorithm employs a circular buffer. Each page receives a reference bit, which is initially set to 0. When a page is accessed, ... Read More
In Swift, there are some different syntaxes to declare an empty dictionary. It is important to remember that all syntaxes produce the same result. In this article, you will see examples of how to declare an empty dictionary and define a dictionary in Swift. What is a Swift Dictionary? A dictionary is a collection in Swift that lets you keep key-value pairs. Each key in the dictionary has a corresponding value, and each word in the dictionary needs to be distinct. Because dictionaries are unordered, the sequence in which key-value pairs are introduced does not matter. Example In this example, ... Read More
Introduction Lottery scheduling is a process scheduling algorithm used in operating systems that assign processes a fixed number of "lottery tickets" based on their priority, determining their likelihood of execution. In this article, we will talk about the lottery process scheduling algorithm, and how can manipulate tickets using the same. The Lottery Process Scheduling Algorithm The higher the priority of a process, the more tickets the lottery process scheduling algorithm receives. In this algorithm, the scheduler chooses a ticket at random from the pool of available tickets. For execution, this algorithm chooses the process that owns the winning ticket. ... Read More
In Swift, you can convert an enum value to a String through the rawValue property. This is if the enum has a raw value of type String. If the enum doesn't have a raw value, you can use the String(describing:) initializer to get a string representation of the enum value. Also, you can use the CustomStringConvertible protocol. Example 1 Convert an enum value to a string using the rawValue property.In this example, Fruit is an enum with a raw value of type String. The rawValue property is used to get a string representation of the myFruit enum value, which is ... Read More
The Longest Remaining Time First (LRTF) scheduling algorithm is a variant of the Longest Job First (LJF) algorithm and is used by the operating system to schedule incoming processes. In LRTF, the process with the highest remaining execution time is given the highest priority and scheduled to be executed first. At intervals of time, such as every unit of time, the system checks to see if another process with a higher burst time has arrived. If such a process exists, it is scheduled for execution before continuing with the current process. The algorithm is designed to maximize the processor's utilization ... Read More
In Swift, when you call a function that throws an error, you must either mark the function call with the try keyword or handle the error using a do-catch block. If you see the error message "Call can throw, but it is not marked with 'try' and the error is not handled", it means that you have called a function that can throw an error, but you have not handled the error properly. How to Fix These Errors? Mark the function call with the try keyword. For example − do { let result = try someFunctionThatCanThrow() ... Read More
Longest Job First (LJF) is a CPU scheduling algorithm that prioritizes processes based on their burst time. In LJF, the processes with the largest burst time are given priority over the shorter ones. This algorithm works on a non-preemptive basis, meaning once a process is started, it will continue to run until it completes, and no other process can preempt it. To implement the LJF algorithm, processes are sorted in the ready queue based on their burst times in descending order. The process with the largest burst time among all the processes that have arrived until that time is selected ... Read More