Last updated on August 14th, 2023 at 01:25 am
Regardless of how good a programmer you are, you will encounter many types of programming errors in your code. Errors appear at different stages in the program implementation phase. To a novice programmer, it is important for you to be able to read and understand these error messages so that you will be able to debug your program competently.
Testing and debugging your program is imperative to ensure you do not deliver a poor product and, therefore, a poor experience for your customers. In this article, we will explore debugging techniques and types of programming errors.
The program implementation phase is not the only time you may encounter errors. Errors may also appear during the problem solving phase. This is why we develop algorithms and use trace tables to test them for correctness.
Types of errors in programming
When writing a computer program, there are several different types of errors. They may be encountered at different stages in the program implementation phase. These types of programming errors are categorized as follows:
- Syntax errors;
- Logic errors; and
- Runtime errors.
What are syntax errors?
A syntax error is a grammatical error in a computer programming language. When a computer program is written in a manner that does not adhere to the rules governing the structure of the language being used, it is called a syntax error.
The Pascal program is a high-level program with a syntax closely resembling the spoken language. As such, it is an easy language to learn, write and debug. It is especially suited to novice programmers.
Runtime Errors
Even when your program passes the first checks and proves to be written in a grammatically correct style, you may still encounter errors when running it. The most obvious ones are runtime errors.
Runtime errors are those that appear or cause a program to crash while it is being run. They may produce the wrong output or cause the program to terminate prematurely. These are usually discovered when a program is going through the testing and debugging phase. However, there are still instances where runtime errors occur when the program is already sold to the end user. In this instance, the programmer develops a patch or an update that a user needs to install to prevent further instances of this error.
What are logic errors in programming
A logic error is a runtime error that does not prevent a program from running but rather causes some unexpected or unintended output. Logic errors usually occur where the structure of the program is grammatically correct. The only indication of the error is usually the unexpected output. This can make logic errors difficult to identify.
Testing your program (Test data)
Testing a program involves checking the program for errors.
This is done at every stage of the program development. Testing goes hand in hand with debugging.
There are two types of tests (testing techniques) conducted by programmers:
- Black box testing and
- White box testing.
White box testing requires the tester to have intimate knowledge of the backend structure of a program. It involves checking the program codes line by line for any syntax errors. This type of testing is usually conducted by program developers.
On the other hand, black box testing requires the tester to have no knowledge of the program structure. It tests the functionality of the program to ensure it performs as required. It also tests usability to see how the user interacts with the program and gain feedback on its appeal. This type of test may be done by software testers.
While writing computer programs, it is often necessary to use if, if-then-else, and nested decision-making in Pascal programming. Be sure to visit our articles on decision-making in Pascal and the case statement in Pascal programming to learn more.
What is test data in program implementation?
Test data is the data chosen to be entered into a program during the testing/debugging process. It includes data designed to check that the program is working as expected.
Test data is also used before the program implementation phase to identify errors in the algorithm.
What is debugging?
While testing is the process of identifying the error in your code, Debugging is identifying the cause of the problem and writing codes to correct the issue. For a programmer, debugging is part of ensuring that your program performs as intended.
Debugging requires that the program be tested extensively to ensure the best quality output for the end user.