<?php
// This is a single-line comment
# This is also a single-line comment
/*
This is a multiple-lines comment block
that spans over multiple
lines
*/
// You can also use comments to leave out parts of a code line
$x = 5 /* + 15 */ + 5;
echo $x;
?>// I'm a single, line comment
# I am another single line comments using #
/*
And I am a
multiline comment
*///
/*
*///For a single line comment use //:
//this is a comment too
//for multi-line comments use /* and */:
/* <--start of multi-line comment
this is a comment
this is a comment too (end of multi-line comment)-->*/Comments do NOT take up processing power.
So, for all the people who argue that comments are undesired because they take up processing power now have no reason to comment ;)
<?php
// Control
echo microtime(), "<br />"; // 0.25163600 1292450508
echo microtime(), "<br />"; // 0.25186000 1292450508
// Test
echo microtime(), "<br />"; // 0.25189700 1292450508
# TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST TEST
# .. Above comment repeated 18809 times ..
echo microtime(), "<br />"; // 0.25192100 1292450508
?>
They take up about the same amount of time (about meaning on a repeated testing, sometimes the difference between the control and the test was negative and sometimes positive).
// This is a single-line comment
# This is also a single-line comment
/*
This is a multiple-lines comment block
that spans over multiple
lines
*/