PHP and MySQL Web Development - P98: PHP and MySQL Web Development teaches the reader to develop dynamic, secure, commercial Web sites. Using the same accessible, popular teaching style of the first edition, this best-selling book has been updated to reflect the rapidly changing landscape of MySQL and PHP. | Programming Errors 457 This script will generate the following error message Parse error parse error in home book public_html chapter23 on line 4 Obviously as our script only has three lines our error is not really on line four. Errors in which you open something but fail to close it will often show up like can run into this problem with single and double quotes and also with the various forms of parentheses. The following script will generate a similar syntax error php if true echo error here These errors can be hard to find if they result from a combination of multiple files. They can also be difficult to find if they occur in a large file. Seeing parse error on line 1001 of a 1000 line file can be enough to spoil your day and act as a subtle hint that you should try to write more modular code. In general though syntax errors are the easiest type of error to find. If you make a syntax error PHP will give you a message telling you where to find your mistake. Runtime Errors Runtime errors can be harder to detect and fix. A script either contains a syntax error or it does not. If the script contains a syntax error the parser will detect it. Runtime errors are not caused solely by the contents of your script. They can rely on interactions between your scripts and other events or conditions. The following statement include is a perfectly valid PHP statement. It contains no syntax errors. This statement might however generate a runtime error. If you execute this statement and does not exist or the user who the script runs as is denied read permission you will get an error resembling this one Fatal error Failed opening required include_path . usr local lib php in home book public_html chapter23 on line 1 Although nothing was wrong with our code because it relies on a file that might or might not exist at different times when the code is run it can generate a runtime error. The following three statements
