how to comment php code example

Example 1: php comment

// 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
*/

Example 2: comment in php

<?php
 /*
    echo 'This is a test'; /* This comment will cause a problem */
 */
?>

Example 3: comment in php

<?php
// Author : https://www.codedweb.org/
// This is a single-line comment
# This is also a single-line comment in unix and linux
  
/*
This is a Multi-lines comment block
by this way you can add muliple lines on it. 
lines
*/
  
// You can also use comments to leave out parts of a code line
$var = 2 /* + 12 */ + 2;
echo $var;
?>

Example 4: comment in php

<?php
    echo 'This is a test'; // This is a one-line c++ style comment
    /* This is a multi line comment
       yet another line of comment */
    echo 'This is yet another test';
    echo 'One Final Test'; # This is a one-line shell-style comment
?>

Example 5: comment in php

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).

Example 6: comments in php

//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)-->*/