(1.4) Identifying and Correcting Errors - PDF.pdf
- 1. Mr. Danzel Umapas - November 16, 2023 Identifying and Correcting Errors Creative Development
- 2. Learning objective: A. Identify the error B. Correct the error
- 3. Debugging
- 4. Debugging Identifying and Correcting Errors • Debugging is the process of fi nding and correcting existing and potential errors (also called bugs) in software code. • Bugs can cause software code to behave unexpectedly or crash. Grace Hopper
- 6. Syntax error
- 7. Syntax errors Identifying and Correcting Errors • These are errors that occur when you have not followed the rules of the language, and they will be fl agged by the translator. • A program with syntax errors will not run. • Common causes of syntax errors: • Spelling or typing errors • Missing parentheses, ( ) or { }, ; in statements in which they are required by the language. • Missing or unexpected indentation in Python • Printing a value without declaring it.
- 8. Logic error
- 9. Logic errors Identifying and Correcting Errors • Errors that cause a program to work incorrectly or unexpectedly. • With a logic error, the program can be run without failing, but it does not return the expected result. • Common causes of logic errors • Not correctly understanding what the program needed to do. • Using the incorrect logical operator in a selection statement. • Missing or incorrect positioning of brackets in mathematical calculations, which means that the incorrect result is returned. • Loops that execute more or fewer times than intended.
- 10. Runtime errors
- 11. Runtime errors Identifying and Correcting Errors • Errors occur when the program is run. They are sometimes also referred to as execution errors. • When the code is valid according to rules of syntax and semantics, and is also logically correct, but the environment that the program is being run in or the input provided causes an error to occur. • Coming causes of runtime errors: • Trying to access a list item that does not exist. • A mathematical calculation that results in the program trying to divide by 0. • Trying to perform numerical operations on strings. • Linking to a fi le or resource that has been moved or longer exists.
- 12. Semantic errors
- 13. Semantic errors Identifying and Correcting Errors •Errors occur where there is improper use of a program code statement, and they are fl agged by the translator.
- 14. Identifying and Correcting Errors Creative Development • A logic error is a mistake in the algorithm or program that causes it to behave incorrectly or unexpectedly. • A syntax error is a mistake in the program when the rules of the programming language are not followed. • A run-time error is a mistake in the program that occurs during the execution of a program. Programming languages de fi ne their own run-time errors. • An over fl ow error is an error that occurs when a computer attempts to handle a number that is outside of the de fi ned range of values.
- 15. Learning Objective: Identify inputs and corresponding expected outputs or behaviors that can be used to check the correctness of an algorithm or program.
- 16. Identifying and Correcting Errors Creative Development • In the development processes, testing uses de fi ned inputs to ensure that an algorithm or program is producing the expected outcomes. • Programmers use the results from testing to revise their algorithms or programs. • De fi ned inputs used to test a program should demonstrates the di ff erent expected outcomes that are at or just beyond the extremes (minimum and maximum) of input data. • Program requirements are needed to identify appropriate de fi ned inputs for testing.
- 17. Identifying and Correcting Errors Creative Development • The following are e ff ective ways to fi nd and correct errors: • Test cases • Hand tracing • Visualization • Debuggers • Adding extra output statement(s)
- 18. We should know… Identifying and Correcting Errors • Before a piece of software can be used, it needs to be tested. • Other testing is more structured and involves a test plan. • When a problem with the software is identi fi ed, the cause will need to be identi fi ed. This is called debugging.
- 20. Things to ponder… Identifying and Correcting Errors •Give at least three (3) examples of errors might occurs during creating a code blocks.
- 21. Identifying and Correcting Errors Creative Development • A logic error is a mistake in the algorithm or program that causes it to behave incorrectly or unexpectedly. • A syntax error is a mistake in the program when the rules of the programming language are not followed. • A run-time error is a mistake in the program that occurs during the execution of a program. Programming languages de fi ne their own run-time errors. • An over fl ow error is an error that occurs when a computer attempts to handle a number that is outside of the de fi ned range of values.
- 22. Things to ponder… Identifying and Correcting Errors •What are the e ff ective ways to fi nd and correct errors?
- 23. Identifying and Correcting Errors Creative Development • The following are e ff ective ways to fi nd and correct errors: • Test cases • Hand tracing • Visualization • Debuggers • Adding extra output statement(s)
- 24. Topic Questions…
- 33. Topics Data • Binary numbers • Data Compression • Extracting Information from Data • Using Programs with Data