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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
In Swift, there are several ways to check whether an index exists in an array. You can use startIndex, endIndex, the indices property, and the count property. In this article, you will see some examples of checking an index. Example 1: Using FirstIndex & EndIndex You can check if a specific index exists in a Swift array by comparing the index against the startIndex and endIndex properties of the array. Here's an example. import Foundation let inputArray = [1, 2, 3, 4, 5] let targetIndex = 3 if targetIndex >= inputArray.startIndex && targetIndex < inputArray.endIndex { print("Index ... Read More
In Swift, you can return multiple values from a function using a tuple. In this article, you will see different examples of how to use a tuple to return multiple values from a function. Here are some more practical examples of functions that return multiple values using tuples in Swift − Example 1 - Parsing a URL into its Components import Foundation func parseURL(urlString: String) -> (scheme: String, host: String, path: String) { guard let url = URL(string: urlString) else { fatalError("Invalid URL") } return ... Read More
In Swift, there are many comparison operators to perform calculations and check different conditions. Less than or greater than operators are used to checking conditional statements. In this article, let's see how to use them with switch and if statements. Less Than or Greater Than the Switch Statement In Swift, you can use the case ..< and case ... syntax to define ranges in a switch statement. The case ..< syntax is used to define a range that includes all values greater than or equal to the first value and less than the second value Step 1 − If ... Read More
In Swift, you can conform to the CustomStringConvertible protocol to provide a default name for each case in an enumeration. This protocol can be used to provide custom meaning as per the requirement. CustomStringConvertible CustomStringConvertible is a protocol in Swift that defines a single property, description, which returns a String representation of an instance of a conforming type. By conforming to CustomStringConvertible, you can customize how your types are represented as strings when they are printed, logged, or otherwise converted to a string. When you conform to CustomStringConvertible, you define how instances of your type are represented as strings by ... Read More