PHP offers an alternative syntax for some of its control structures; namely, if, while, for, foreach, and switch. In each case, the basic form of the alternate syntax is to change the opening brace to a colon (:) and the closing brace to endif;, endwhile;, endfor;, endforeach;, or endswitch;, respectively.
<?php if ($a == 5): ?>
A is equal to 5
<?php endif; ?>
In the above example, the HTML block "A is equal to 5" is nested within an if statement written in the alternative syntax. The HTML block would be displayed only if $a is equal to 5.
The alternative syntax applies to else and elseif as well. The following is an if structure with elseif and else in the alternative format:
if ($a == 5):
echo "a equals 5";
elseif ($a == 6):
echo "a equals 6";
echo "a is neither 5 nor 6";
Note: Mixing syntaxes in the same control block is not supported.