PHP Compilation of Errors and Warnings
Notice: Undefined index[edit | edit source]
Trying to access an array by a key that does not exist in the array
Possible Solution :
Check the availability before accessing it. Use:
Warning: Cannot modify header information - headers already sent[edit | edit source]
Happens when your script tries to send a HTTP header to the client but there already was output before, which resulted in headers to be already sent to the client.
Possible Causes :
Print, echo: Output from print and echo statements will terminate the opportunity to send HTTP headers. The application flow must be restructured to avoid that.
Raw HTML areas: Unparsed HTML sections in a .php file are direct output as well. Script conditions that will trigger a
header() call must be noted before any raw blocks.
<!DOCTYPE html> <?php // Too late for headers already.
<?php for "script.php line 1" warnings: If the warning refers to output in line 1, then it's mostly leading whitespace, text or HTML before the opening
<?php # There's a SINGLE space/newline before <? - Which already seals it.
Parse error: syntax error, unexpected T_PAAMAYIM_NEKUDOTAYIM[edit | edit source]
"Paamayim Nekudotayim" means "double colon" in Hebrew; thus this error refers to the inappropriate use of the double colon operator (
::). The error is typically caused by an attempt to call a static method that is, in fact, not static.
If the above code causes this error, you most likely need to simply change the way you call the method:
The latter example assumes that
$classname is an instance of a class, and the
doMethod() is not a static method of that class.