The require() statement includes and evaluates the specific file.
require() includes and evaluates a specific file. Detailed information on how this inclusion works is described in the documentation for
require() and include() are identical in every way except how they handle
failure. include() produces a Warning while require() results in a
Fatal Error. In other words, don't hesitate to use require() if you want a missing file to halt processing of the page. include() does not behave this way, the script will
continue regardless. Be sure to have an appropriate include_path setting as well.
Example 16-4. Basic require() examples
See the include() documentation for more examples.
Note: Prior to PHP 4.0.2, the following applies: require() will always attempt to read the target file, even if the line it's on
never executes. The conditional statement won't affect require(). However, if the line on which the require() occurs is not executed, neither will any of the code in the target file be executed. Similarly, looping structures do not affect the
behaviour of require(). Although the code contained in the target file is still subject to the loop, the require() itself happens only once.
Note: Because this is a language construct and not a function, it cannot be called using variable functions
Windows versions of PHP prior to PHP 4.3.0 do not support accessing remote files via this function, even if allow_url_fopen is enabled.
See also include(), require_once(), include_once(), eval(), file(), readfile(), virtual() and include_path.