Several small mistakes that PHP novices often make

This article lists several small mistakes that PHP novices often make for your reference.

1. header already sent This error usually occurs when you use HEADER. It may be due to several reasons: 1. You PRING or ECHO before using HEADER 2. There is a blank line in front of your current file 3. You may have INCLUDEd a file. This error will also occur if there is a blank line at the end of the file or the output. !

2. Variables cannot be passed between pages The automatic global variables of get, post, and session are turned off in the latest PHP version, so to get the submitted variables from the previous page, use $_GET['foo'],$ _POST['foo'],$ _SESSION['foo'] to get. Of course, you can also modify the automatic global variables to be on (php.ini changed to reGISter_globals = On); considering compatibility, it is better to force yourself to become familiar with the new writing method.

3. Using the get method to pass Chinese parameters to apache2 under Win32 will cause an error: test.php?a=Hello&b=Hello Passing parameters will cause an internal error ​ Solution: "test.php?a=".urlencode(Hello)."&b=".urlencode(Hello) .............

4. The session under win32 does not work properly. php.ini default session.save_path = /tmp This is obviously a configuration under Linux. PHP under win32 cannot read and write the session file, causing the session to be unusable. Just change it to an absolute path, for example, session.save_path = c:Windows emp

5. Mail() cannot send emails under Win32 Sendmail configured under Linux can be sent. Under win32, you need to call the smtp server to send emails. Modify SMTP = ip in php.ini //ip is an smtp server without verification function (hard to find on the Internet) The best solution for sending emails in PHP is to use socket to send directly to the other party's email server without forwarding the server.

6. If the password is not set for the initial installation of MySQL, you should use update mysql.user set password="yourpassword" where user="root" to change the password

7. Display error message When display_errors = On and error_reporting = E_ALL in php.ini, all errors and prompts will be displayed. It is best to turn it on during debugging for error correction. If you use the previous PHP writing method, most of the error messages will be about undefined variables. There will be a prompt when a variable is called before it is assigned a value. The solution is to detect or shield it. For example, to display $foo, you can if(isset($foo)) echo $foo or echo @$foo