Software Development Visual Lecture Notes

Software Development Now that you have explored a variety of software, we will how it is all created. As you remember from Chapter 1, software is made from computer programs that detailed instructions for the computer. To create successful software, computer programmers go through of steps known as the software development life cycle (SDLC). This cycle takes programmers from the planning stages through the actual programming, testing, and maintenance of the software. In this we will explore some fundamental concepts in computer programming by taking a quick tour of the evelopment stages. Notes for section starting with "Now that you" +New Note to Section Figure 3.2 Flowchart Tracing Steps of a Program PLANNING Like most things you do on a daily basis, software development begins with an idea and a plan. Programmers must come up with a detailed description of the tasks they want their software to accomplish. They will come up with a series of steps, known as an algorithm, that describes exactly what each portion of their program is supposed to do. This algorithm is often represented visually as a flowchart, which uses special symbols to trace the steps of the program (see Figure 3.2). Once programmers have developed their algorithms and flowcharts, they essentially have a blueprint or guide that will allow them to start writing their program. Notes for section starting with "Like most things" +New Note to Section If you have trouble understanding this stage of development, imagine for a moment the process you go through to cook and eat hamburgers for dinner. Not only do you need to come up with an idea of what you want to eat, you must also create a plan for successfully preparing the hamburgers. From heating the grill to cutting vegetables while the hamburgers cook, you probably have developed a series of steps you follow to prepare this or any other meal. For more complex dishes, you likely have a recipe with detailed ingredients, notes, and steps that you must review before you start cooking. This is the sort of planning that programmers must engage in before they start work on the actual coding of the program. Notes for section starting with "If you have" +New Note to Section CODING In this phase, the programmer will begin the process of converting the algorithms and flowcharts into an actual computer program, a process known as coding. Notes for section starting with "In this phase," +New Note to Section The code created by these programmers is written in one of many computer programming languages that contain their own vocabulary and grammar (syntax), much like English, Spanish, and practically every other language. Although these programming languages use many words that you would immediately recognize, they also use complex symbols and sequences that require a great deal of training to master. The following are some of the most popular programming languages for creating computer software: Notes for section starting with "The code created" +New Note to Section C++ Java C# Python Notes for section starting with "C++ Java C#" +New Note to Section Many programmers today use an integrated development environment (IDE), which is software that helps them build their computer programs. This software, such as Microsoft Visual Studio, provides a variety of tools and features that can increase the programmer’s speed and accuracy. In addition, these IDEs contain a compiler, which is a program that translates a specific programming language into a machine language that can be processed by the CPU. Once a computer program is compiled, the IDE will produce an executable file that can be run by the operating system on a user’s computer. Notes for section starting with "Many programmers today" +New Note to Section TESTING AND MAINTENANCE In the same way you test and adjust a recipe to make it as perfect as possible, software must also go through a process after it is created. First, a programmer will look for errors, or bugs, by testing the software under a series of conditions. The process of finding and fixing these bugs is known as debugging. Once this phase is over, programmers might want to test the software in real-world conditions. They will release a beta version to a limited audience that will test it on their systems. Programmers can now collect information from these users about any errors encountered. Notes for section starting with "In the same" +New Note to Section Once the software is deemed ready, it is released to the general public. However, no software is truly free of bugs. Errors and security vulnerabilities will continue to be found, and programmers will “patch” them by offering software updates to users. It is crucial that you download and install all software updates (especially for the operating system) the moment they are released. Most software does this automatically, requiring only an occasional restart of the program or your computer. Some updates may also include improvements and new features that many users desire. Programmers will continue to update and maintain the software until the company decides to no longer support this software or one of its particular versions.