A Beginner’s Guide to Big O Notation « Rob Bell. Big O notation is used in Computer Science to describe the performance or complexity of an algorithm. Big O specifically describes the worst-case scenario, and can be used to describe the execution time required or the space used (e.g. in memory or on disk) by an algorithm. Anyone who’s read Programming Pearls or any other Computer Science books and doesn’t have a grounding in Mathematics will have hit a wall when they reached chapters that mention O(N log N) or other seemingly crazy syntax. Hopefully this article will help you gain an understanding of the basics of Big O and Logarithms. As a programmer first and a mathematician second (or maybe third or fourth) I found the best way to understand Big O thoroughly was to produce some examples in code. So, below are some common orders of growth along with descriptions and examples where possible. O(1) describes an algorithm that will always execute in the same time (or space) regardless of the size of the input data set.
Logarithms. Top 10 Things Every Software Engineer Should Know. Please take a second to look at our brand new Java Resource Collection. The following top ten list collects some important things I have learned in the last eighteen years as IT professional. It is a very personal selection and doesn’t necessarily reflect the opinion of a software engineering organisation. There is no strict ranking in the list – though I tried to put the more important things to the top.The technical and business know-how is more important for young software engineers and the soft skills getting increasingly relevant for senior software engineers. 1) Fundamentals of Emotional Intelligence Almost all of us work with a lot of people.
During my professional life, I attended some so called soft skill courses. The Wikipedia definition of Emotional intelligence starts with the sentence “Emotional intelligence (EI) is the ability to identify, assess, and control the emotions of oneself, of others, and of groups.” [1] The important key word in this sentence is emotions. Writing Maintainable Code. Introduction The success rate for software development projects around the world is shameful. Projects are very often delivered late or over budget, which is acceptable because the alternative seems to be not delivering the project at all. Certainly there are things in the development lifecycle that are out of the developer's hands, such as the quality of the requirements.
However, one cause of poor software delivery success rates is that applications with large amounts of code can quickly become unmanageable, tangled messes that no one wants to touch. Write For the Person Who Will Maintain Your Code Unless you work for yourself, the code you write will likely be touched by someone else at one time or another. Variable/Method Names I'm not going to advocate the use of any particular notation or convention.
One thing you should focus on is making readable variable, function, and object names. Object s = this.GetSaxophone(); Object saxophone = this.GetSaxophone(); Short Methods Refactoring. Six ways to write more comprehensible code. I learned to write, clear, maintainable code the hard way. For the last twelve years, I've made my living writing computer games and selling them over the Net using the marketing technique that was once charmingly known as shareware. What this means is that I start with a blank screen, start coding, and, a few tens of thousands of lines of code later, I have something to sell. This means that, if I make a stinky mess, I'm doing it in my own nest. When I'm chasing down a bug at 3 a.m., staring at a nightmare cloud of spaghetti code, and I say, "Dear God, what idiot child of married cousins wrote this garbage?
" So I have been well rewarded by learning about good, sane programming techniques. But there are many who, like me, stumbled into programming in an unexpected or unusual way and never had anyone drill this stuff into them. The example case For illustration purposes, our example program throughout this article is a hypothetical computer game called Kill Bad Aliens. Figure 1. Oh? Www.labri.fr/perso/casteran/distribC/reuse. On Writing Maintainable Code. A QUICK NOTE: This was supposed to be a single treatise on the coding and design principles that *I* think are most important for writing maintainable code.
A draft of this has been on my hard drive for a long, long time and it's turning into my own great white whale. Just to get it out, I'm breaking it into pieces that will follow shortly, depending on ongoing bouts with writer's block. I'm going to intermix quick discussions of these design concepts with some case studies of systems I've built or worked with that illustrate both the positive outcome of following the principles and the pain incurred by failing to apply the principles. Some day, I'll gather the pieces back up into a single coherent article. Enable Change or Else! Change is a constant in an enterprise software system. I spent much of the past two years at my previous job extending, restructuring, or flat out re-writing legacy code. Extensibility yes, but how?
Coder to Craftsman The Maintainable Code Checklist Orthogonality.