C++ Programming/Code

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[edit] The Code

The task of programming, while not easy in its execution, is actually fairly simple in its goals. A programmer will envision, or be tasked with, a specific goal. Goals are usually provided in the form of "I want a program that will perform...fill in the blank..." The job of the programmer then is to come up with a "working model" (a model that may consist of one or more algorithms). That "working model" is sort of an idea of how a program will accomplish the goal set out for it. It gives a programmer an idea of what to write in order to turn the idea in to a working program. Once the programmer has an idea of the structure their program will need to take in order to accomplish the goal, they set about actually writing the program itself with all of the proper commands, functions and syntax. The code that they write is what actually implements the program, or causes it to perform the necessary task, and for that reason, it is sometimes called "implementation code".

How the instructions of a program are written out and stored is generally not a concept determined by a programming language. Punch cards used to be in common use, however under most modern operating systems the instructions are commonly saved as plain text files that can be edited with any text editor. These files are the source of the instructions that make up a program and so are sometimes referred to as source files but a more exclusive definition is source code.

When referring to source code or just source, you are considering only the files that contain code, the actual text that makes up the functions (actions) for computer to execute. By referring to source files you are extending the idea to not only the files with the instructions that make up the program but all the raw files resources that together can build the program.

Source code

Source code is the halfway point between human language and machine code. As mentioned before, it can be read by people to an extent, but it can also be parsed (converted) into machine code by a computer. The machine code is the strings of 1's and 0's that the computer can fully understand and act on.

In a small program, you might have as little as a few dozen lines of code at the most, whereas in larger programs, this number might stretch into the thousands or even millions. For this reason, it is sometimes more practical to split large amounts of code across many files. This makes it easier to read, as you can do it bit by bit, and it also reduces compile time of each source file. It takes much less time to compile a lot of small source files than it does to compile a single massive source file.

Managing size is not the only reason to split code, though. Often, especially when a piece of software is being developed by a large team, source code is split. Instead of one massive file, the program is divided into separate files, and each individual file contains the code to perform one particular set of tasks for the overall program. This creates a condition known as Modularity. Modularity is a quality that allows source code to be changed, added to, or removed a piece at a time. This has the advantage of allowing many people to work on separate aspects of the same program, thereby allowing it to move faster and more smoothly. Source code for a large project should always be written with modularity in mind. Even when working with small or medium sized projects, it is good to get in the habit of writing code with ease of editing and use in mind.

C++ source code is case sensitive. This means that it distinguishes between lowercase and capital letters, so that it sees the words "hello," "Hello," and "HeLlO" as being totally different things. This is important to remember and understand, it will be discussed further in the Coding Style Section.