Can someone explain the difference between using
define('SOMETHING', true);
and
$SOMETHING = true;
And maybe the benefits between one or the other?
I use variables everywhere and even in a config type file that is included to everypage I still use variables as I don't see why to use the define method.
In all cases the second won't be faster, since you are supplying a double-quoted string, which have to be parsed for variables as well. If you are going for micro-optimization, the proper way is:
$message = sprintf('The request %s has %d errors', $request, $n);
Still, I believe the seconds is slower (as @Pekka pointed the difference actually do not matter), because of the overhead of a function call, parsing string, converting values, etc. But please, note, the 2 lines of code are not equivalent, since in the second case $n is converted to integer. if $n is "no error" then the first line will output:
The request $request has no error errors
While the second one will output:
The request $request has 0 errors
Here's what worked best for me when trying to script this (in case anyone else comes across this like I did):
$ pecl -d php_suffix=5.6 install <package>
$ pecl uninstall -r <package>
$ pecl -d php_suffix=7.0 install <package>
$ pecl uninstall -r <package>
$ pecl -d php_suffix=7.1 install <package>
$ pecl uninstall -r <package>
The -d php_suffix=<version> piece allows you to set config values at run time vs pre-setting them with pecl config-set. The uninstall -r bit does not actually uninstall it (from the docs):
vagrant@homestead:~$ pecl help uninstall
pecl uninstall [options] [channel/]<package> ...
Uninstalls one or more PEAR packages. More than one package may be
specified at once. Prefix with channel name to uninstall from a
channel not in your default channel (pecl.php.net)
Options:
...
-r, --register-only
do not remove files, only register the packages as not installed
...
The uninstall line is necessary otherwise installing it will remove any previously installed version, even if it was for a different PHP version (ex: Installing an extension for PHP 7.0 would remove the 5.6 version if the package was still registered as installed).
The main differences:
1.) you can use "normal" output syntax, so for example an echo statement. You don't have to rewrite your problem.
2.) you have better control about the buffering, since buffers can be stacked. You don't have to know about naming conventions and the like, this makes implementations easier where the writing and using side are implemented separate from each other.
3.) no additional logic require to output buffered content, you just flush. Especially interesting if the output stream is something special. Why burden the controlling scope with dealing with that?
4.) you can use the same output implementation regardless of an output buffer has been created. THis is a question of transparency.
5.) you can 'catch' accidentially out bubbled stuff like warnings and the like and simply swallow it afterwards.
[...]
Never used any of those, but they look interesting..
Take a look at Gearman as well.. more overhead in systems like these but you get other cool stuff :) Guess it depends on your needs ..
DEFINE makes a constant, and constants are global and can be used anywhere. They also cannot be redefined, which variables can be.
I normally use DEFINE for Configs because no one can mess with it after the fact, and I can check it anywhere without global-ling, making for easier checks.