A computer program is a set of instructions for the system to interpret. These instructions should be written clearly and accurately, taking into account the user interface, user experience and features. It is important to consider the machine would be as capable of understanding as a person, and so avoid any spelling or grammatical errors.
Machines lack the ability to use heuristics to interpret a command that is not clearly articulated, meaning that a single incorrect punctuation mark could cause hundreds of lines of code to be rendered ineffective. This could result in the code either not running at all or not functioning as anticipated, making it necessary to identify and address any software flaws, referred to as bugs.
Testing can help us to identify the result of an issue, however, it does not necessarily provide insight into the cause. Similar to Python‘s interpreter, certain error outputs may attempt to provide an educated guess as to what the mistake may be in order to aid the developer. However, some people may be difficult to understand and frustrating.
Despite software developers‘ best efforts, it can be difficult to avoid producing flawed software. Consequently, debugging is a vital part of the software development process. Fortunately, debugging can be highly beneficial throughout the development process, resulting in creative solutions that can improve the program.
When estimating time, how long does debugging often take?
Non-developers are often surprised to discover that debugging can take more time than coding. A significant proportion of the work involved in software development is dedicated to testing, debugging and maintenance, rather than creating the code itself.
It is imperative that we take measures to prevent bugs from occurring. Defensive programming is one of the most common approaches to doing so. A more detailed discussion of this technique is beyond the scope of this text, but it essentially involves ensuring that code is prepared to handle any potential issues.
Visualising a highway with other motorists as end consumers is a helpful metaphor for software developers. Even if a function is designed perfectly, it can still fail due to incorrect input from the end consumer. Therefore, it is important for designers to put safeguards in place to prevent this from happening.
The question is, what exactly creates bugs?
In general, errors may be sorted into the following categories:
Logical or semantic errors can occur when the syntax of the code is correct, but the meaning is not. This can lead to unexpected results, similar to opening an oven and discovering chicken rather than the pizza that was expected due to following a different recipe. On closer inspection, it is revealed to be a chicken dish recipe.
Flaws in the implementation:
The high-level code is performing as expected, however, there are issues present with the underlying data structures which are resulting in unexpected behaviour or the program crashing. For example, attempting to reorder the elements of a tuple (a data structure which is ordered and immutable) using a Python function will not have any effect.Mistakes, typos, and easy misunderstandings:
Incorrectly using a logical operator or referencing the wrong variable can be likened to spelling mistakes or incorrect punctuation.Errors in syntax:
The machine is unable to process the code due to an error. This is likely due to the use of a semicolon as a line terminator in various computer languages. Without a semicolon, the computer may interpret the lines below as part of the same command.
Issues with bugs can indicate a more complex underlying issue. In some instances, the defect might be precise in terms of its location; in other situations, the developer will need to carefully examine the code to locate the source of the problem. This is achievable when dealing with a small codebase of a few hundred lines, however contemporary software often incorporates millions of lines of code dispersed across multiple files. For this reason, debugging techniques are essential.
Which methods of debugging are the most often used?
As the developer writes the code, tests are conducted at predetermined intervals to ensure that it is operating as expected. However, this does increase the time taken for the coding process.
Visualization:
Software engineers use the incremental development method to evaluate the running program, by printing outputs and consulting console logs. This process is often divided into smaller sections, allowing for closer examination of the data manipulation within each stage.Fix Bugs Using debuggers:
Debugging software, which is used to detect errors in other software, is commonly found in most popular programming languages. Such software often contains a vast amount of data which can be utilised by the programmer to pinpoint the problem.Eliminating Unnecessary complexity:
The developer begins by breaking the code down into manageable parts, then gradually increases the code’s complexity until the bug is discovered.Clustering defects:
It is likely that all the associated issues can be traced back to a single underlying cause. To gain a better understanding of the origin of the problem, it would be beneficial to separate the errors into different groups. This approach is similar to that of a doctor who uses a variety of signs and symptoms to make a diagnosis.Backtracking:
The developer just starts with the mistake and works backwards through the code to locate the cause.
There are numerous approaches and styles available for debugging code, and this is only a selection. It is clear that debugging requires engineers to go through the code multiple times in order to identify and resolve any potential issues.
By reviewing the code and attempting to identify the source of a problem, the development team can take a step back and review their prior work with a fresh perspective. This can often lead to improvements to the software’s structure and performance, much like adjusting the settings on a car.
In what capacity does the customer serve?
It is essential that the client is involved in the debugging process, especially with incremental development or within agile teams, as they act as testers. Clients are often the best testers as they are most familiar with their requirements and expectations.
As a result of the first-hand knowledge of the service’s end users, the development team will be able to locate and fix more bugs. Therefore, it is essential that the customer provides as much information as possible when reporting an issue, and should accept and deliver the report if the team is using a data-gathering tool. The more information that is available to the team, the more quickly and effectively any bugs can be resolved.
The development of software requires a complex network of communication between developers, customers and the technology in use. Streamlined information sharing is essential to the successful delivery of any project. By viewing debugging as a way to facilitate communication within the system, rather than a quick fix to an inadequate job, we can work together to produce the best possible outcome.
