PHP Tutorials - Whitespace Insensitive and Case sensitive

PHP Whitespace Insensitive

In this chapter we will study about PHP whitespace Insensitive and Case Sensitive but before we go ahead first of all we should know that what whitespace is?

Whitespace is a character which is ‘Typed’ but it remains invisible on the screen. Typically it includes space, tabs, line changes etc.

PHP is whitespace insensitive language that ignores whitespaces. This means many whitespace characters are same to one whitespace character. Check out below example the try on your text editor.

Example - 1

<?php
 $x = 'https://www.progrramers.       com   '; //Whitespace is invisible on web page
 
 $y = 'https://www.progrramers. com';   //both will produce same result
 
  echo '<a href = "https://www.progrramers.com">' .$x. '</a> <br />';
  
  echo '<a href = "https://www.progrramers.com">' .$y. '</a> <br />';
 ?>

PHP Case sensitive

If you ever heard that PHP is case sensitive than it is true PHP is case sensitive language but there is one condition here. In PHP, all keywords like if, else, while, echo, etc., classes, functions, and user-defined functions are NOT case-sensitive. You can see yourself in below example

Example - 2

<?php
 $CAR = 'Skoda';
 
  echo $CAR;
  
  echo $car;
  
  echo $Car;
 ?>

All the variables in PHP are case sensitive. In above example you can see that $Car, $car and $CAR are not similar.  We will study about variables in next chapter.