PHP/Basic Code

Basics

.php

all PHP pages end with the .php extension, this tells the browser there is php code in the file.

//

comments in PHP are defined with a double-forward slash "//"

unlike most other comments which have delimiters both before and after comments, PHP does not, the "//" is defined at the beginning of the comment and the rest of the line is then included as part of the comment.

delimiters - start & stop

<?php

all php code begins with this.

?>

all php code ends with this

output text

echo

just like with scripting, echo can be used to output text

ie.
<p>
 <?php
   echo "My first line of PHP!"; 
 ?>
</p>

Arithmetic

php is capable of doing basic arithmetic, take the following for example using "echo"

<?php
 echo 17 * 123;  
?>
Outputs: 2091

Operators

concatenation

joins strings together

<?php
 echo "Hello," . " " . "world" . "!";
?>
----
Outputs: Hello, world!

Each string above is defined between double quotes. The "dots" are between them and combine them together to form 1 long string.

Variables

Variables in php are stored the same way as bash scripting, the variable name being defined by starting with a "$"

ie.
<?php
 $myName = "r00tedvw";
 echo $myName;
?>

Comparisons

>

Greater than

<

Less than

<=

Less than or equal to

>=

Greater than or equal to

==

Equal to

!=

Not equal to

If/Else

example:

<?php
  if (this condition is true) {
    // do this code
  }
  else {
    // do this code instead
  }
?>

<?php
       // Write your if/elseif/else statement here!
       $myAge = 34;
       if ($myAge < 30) {
           echo "The condition is true";
       }
       else {
           echo "The condition is false";
       }
?>