Alternate method of calling PHP language constructs
This is a minor note, but while echo looks like a function call, it is actually instead considered a language construct — that is, a piece of code that makes up the PHP language.
You can actually write this line another way.
<?php echo('Hello world!');
Rather than wrapping the string in parentheses, you can eliminate them! Just leave a space between echo and the string.
<?php echo 'Hello world!';
There are many other language constructs. Some require parentheses, some do not.
There are no performance implications of using either method, so you can use whatever you wish. You don’t need to memorize these, because I’d recommend using parenthesis absolutely everywhere anyways, as it will make your code easier to read and understand.
There is one exception though, and that is probably the
echo construct. Since this construct is used so often and usually deals with outputting strings, I’d say it’s actually easier to read through echo statements if they do not use parentheses. So, this is the approach I take: everything uses parentheses besides echo.