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If any transaction that performs a dirty read operation from an uncommitted transaction and also its committed operation becomes delayed till the uncommitted transaction is either committed or rollback such type of schedules is called as Recoverable Schedules.Types of recoverable schedulesThere are three types of recoverable schedules which are explained below with relevant examples −Cascading schedulesCascadeless SchedulesStrict Schedules.The types of recoverable schedules are given below in form of a chart −Recoverable scheduleFirst, let us see an example of a recoverable schedule.T1T2R(X)W(X)W(X)R(X)commitCommitHere, transaction T2 is reading value written by transaction T1 and the commit of T2 occurs after the commit of ... Read More
The Hashtable collection in C# is a collection of key-value pairs that are organized based on the hash code of the key. The hash code is calculated using a hash code function. Each element in the hashtable is a key-value pair with unique keys. Keys also have to be nonnull. Values can be null and duplicated. In this article, we will discuss how to check if the hashtable collection is empty. How to Check if the Hashtable Collection is Empty? The class in C# that implements the hashtable collection is the Hashtable class. We can check if the hashtable collection ... Read More
Introduction One of the most essential mathematical notations in computer science for determining an algorithm's effectiveness is the Big O notation. The length of time, memory, other resources, as well as a change in input size required to run an algorithm can all be used to evaluate how effective it is. Data structure's Big O Notation provides information about an algorithm's performance under various conditions. In other words, it provides the worst-case complexity or upper-bound runtime of an algorithm. Big O Notation in Data Structure A change in input size can affect how well an algorithm performs. Asymptotic notations, such ... Read More
Since Array and NSArray are both core constructs in iOS development, we sometimes forget just how different they are. Here are some major differences between the two constructs that you should know about. Array is a struct, therefore it is a value type in Swift. NSArray is an immutable Objective C class, therefore it is a reference type in Swift. Array is a Swift construct, and generic struct, which means that it can be an array of any specific type (Int, String, etc.). [T] is syntactic sugar for Array. NSArray is an Objective-C construct that can hold any Objective-C ... Read More
Throughout this article, you will learn what an attribute in Swift is and how to use it with code examples. Swift Attributes Swift makes it possible to provide some additional info about the declaration or type. We have two types of attributes that can be used in Swift language. Declaration Attributes Type Attributes Syntax You can apply an attribute by using the symbol @ followed by the attribute name, as shown below − @attribute name @attribute name(attribute arguments) Explanation We can provide arguments in declaration attributes to define the declaration. These arguments can be provided in parentheses ... Read More
In this article, you will learn about what Delegate is and how it works. What is Delegation? As the name implies, delegation gives control to other objects. To make it happen, the delegate object has to be assigned to control other objects. In iOS apps, the UIApplicaitonDelegate is an example. UIApplicationDelegate allows you to modify iOS behavior, such as receiving push notifications, opening URLs, and launching apps. A delegation pattern ensures the functionality that needs to be delegated is provided. Delegate patterns enable objects to communicate back to their owners decoupled from their code. It is much easier to ... Read More
In this article, you will learn about the different execution states of an iOS application. Based on the current state, you can decide what task you want to perform. There are different states that an app might have. The iPhone operating system (iOS) provides us with different five states of an application like the following − Not running Inactive Active Background Suspended An iOS application runs in several states, known as states of the application life cycle. App life cycles are crucial for iOS developers, as they help them understand how their apps behave. The following states are ... Read More
In this article, we will discuss Swift's comments, why, and how to use them correctly in Swift. Always keep one thing in mind while writing code i.e. The code must be written for people to read and understand as much as possible. Similarly to the Swift language, comments are very useful for making your code more easily understandable to you and other developers. All the comments in the code are completely ignored by the Swift compiler. There are two types of comments in Swift − Single Line Comments Multiline Comments Single Line Comments Syntax Swift allows us to ... Read More
Declaring variables as optional is always recommended and should be the first choice of a developer. You should mark them as optional if they can be invalid (nil or another type). Being developers, we consider it our responsibility to write safe and secure code. To make it possible, Swift provides us with many concepts, and optional is one of them. The optional variable might contain a nil value, so we have to get its value safely. There are a couple of ways to unwrap the value of an optional variable. Let's learn about them. First, we need to understand what ... Read More
Introduction This article will guide you about the usage of Class and what are the benefits of using inheritance in the Swift language. In this article, we will cover the following things − What is a class and what is its usage in Swift? What is inheritance and what are its benefits? What is a Class? In the Swift language, a class is a representation of properties and methods. We use classes to encapsulate properties and methods into a single entity that has the same characteristics. We use classes to store information in variables and constants. A class ... Read More