While it is much easier and more efficient to use a debugger such as x-debug to debug your PHP web application, there may be some difficulties on the server stopping one from implementing x-debug.\u00a0 In this case, we are forced to use the classic debug methods instead.\u00a0 This article will elaborate on the implementing classic methods in web programming.<\/p>\n
Displaying Debug Messages<\/b><\/p>\n
The simplest way to debug is to display debug messages.\u00a0 The standard PHP function to do this is “ One disadvantage is that having these extra displays, if left in the production code, there could be unprofessional looking displays on the website.\u00a0 To avoid this, one should always check the diff before checking in the code.\u00a0 But then again, if the problem occurs on production, you will never be able to use this method to debug, as it will disrupt the website.\u00a0 To avoid this potential pitfall, there are alternatives.<\/p>\n One alternative debugging method is writing it to a log.\u00a0 This will enable to website to display correctly, while the error may be checked only by those with access to the log.\u00a0 In addition, one can set up their system to write to the log in different events in order to diagnose potential issues and monitor system behavior.\u00a0 Another possibility is to use a tool such as firePHP (a Firefox plugin), in order to have messages only displayed in the firePHP.\u00a0 This may allows the developer to check without having to access a log.\u00a0 Still, since anyone can install firePHP and view your confidential debugging messages, it is best to have it turned off in production.<\/p>\n “Oy Vey” Debugging \u2013 Forcing a Crash<\/b><\/p>\n One problem with the previous approach is that the method is prone to failure.\u00a0 The log could fail to be written for a\u00a0 number of reasons.<\/p>\n Another issue is that, while displaying or logging a message will indicate that a line of code was executed, it will might not tell you how you got there.\u00a0 You can still use The error screen now displays all the info you need.<\/p>\n Still, some systems will trap your errors, so in order to force a fatal error by calling a non-existent function.<\/p>\nvar_dump()<\/code>“.\u00a0 var_dump()<\/code> can be used to display data, including arrays and objects.\u00a0 With large objects or arrays, the data may be truncated, so you may need to specify the element in the array or object or specifically cast it to a string if it is a virtual string.\u00a0 You can also use var_dump()<\/code> or echo<\/code> to confirm that a certain line was indeed executed.<\/p>\nvar_dump()<\/code> and echo could be disabled if the system buffers and flushes the output.\u00a0 Using third-party plugins is also not 100% reliable. \u00a0Browsers and plugins are always being updated, and new versions can have compatibility issues.<\/p>\ndebug_backtrace()<\/code>, but there is another way.<\/p>\ntrigger_error('oy vey');<\/code><\/p>\nthrow new Exception('oy vey');<\/code><\/p>\n