Book Image

C# 7 and .NET: Designing Modern Cross-platform Applications

By : Mark J. Price, Ovais Mehboob Ahmed Khan
Book Image

C# 7 and .NET: Designing Modern Cross-platform Applications

By: Mark J. Price, Ovais Mehboob Ahmed Khan

Overview of this book

C# is a widely used programming language, thanks to its easy learning curve, versatility, and support for modern paradigms. The language is used to create desktop apps, background services, web apps, and mobile apps. .NET Core is open source and compatible with Mac OS and Linux. There is no limit to what you can achieve with C# and .NET Core. This Learning Path begins with the basics of C# and object-oriented programming (OOP) and explores features of C#, such as tuples, pattern matching, and out variables. You will understand.NET Standard 2.0 class libraries and ASP.NET Core 2.0, and create professional websites, services, and applications. You will become familiar with mobile app development using Xamarin.Forms and learn to develop high-performing applications by writing optimized code with various profiling techniques. By the end of C# 7 and .NET: Designing Modern Cross-platform Applications, you will have all the knowledge required to build modern, cross-platform apps using C# and .NET. This Learning Path includes content from the following Packt products: • C# 7.1 and .NET Core 2.0 - Modern Cross-Platform Development - Third Edition by Mark J. Price • C# 7 and .NET Core 2.0 High Performance by Ovais Mehboob Ahmed Khan
Table of Contents (25 chapters)
Title Page
Copyright
About Packt
Contributors
Preface
16
Designing Guidelines for .NET Core Application Performance
Index

Understanding the use of Big O notation to measure the performance and complexity of an algorithm


Big O notation is used to define the complexity and performance of an algorithm with respect to time or space consumed during execution. It is an essential technique to express the performance of an algorithm and determine the worst-case complexity of the program.

To understand it in detail, let's go through some code examples and use Big O notation to calculate their performance.

If we calculate the complexity of the following program, the Big O notation will be equal to O(1):

static int SumNumbers(int a, int b) 
{ 
  return a + b; 
} 

This is because, however the parameter is specified, it is just adding and returning it.

Let's consider another program that loops through the list. The Big O notation will be determined as O(N):

static bool FindItem(List<string> items, string value) 
{ 
  foreach(var item in items) 
  { 
    if (item == value) 
    { 
      return true; 
    } 
  } 
  return...