Exercise : Buggy PHP

The following PHP pages each contain one or more bugs. The bugs could be syntax errors or incorrect logic. Look at each page, find the bug(s), and correct the errors.

1. buggy page 1 (source) - variables, strings, if/else
2. buggy page 2 (source) - variables, if/else, comments
3. buggy page 3 (source) - variables, for loops, string concatenation
4. buggy page 4 (source) - arrays, foreach
5. buggy page 5 (source) - arrays, foreach

Exercise debugging tips

• Look at the error messages, if any, and examine those lines in your PHP source file. (You may need to enable line numbers in your editor.)
• Check for mismatched brackets. Many editors support bracket matching.
• PHP's error messages are not very friendly, often mentioning internal terms like T_VARIABLE and $end. If you don't understand an error, try Googling for the error message.
• If there is no error message, try printing the value of variables at various points in the code. Use print for simple variables and print_r or var_dump for arrays and objects.

Exercise solutions

1. buggy page 1, fixed
2. buggy page 2, fixed
3. buggy page 3, fixed
4. buggy page 4, fixed
5. buggy page 5, fixed