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. A is equal to 5 ]]> 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: ]]> Mixing syntaxes in the same control block is not supported. Any output (including whitespace) between a switch statement and the first case will result in a syntax error. For example, this is invalid: ... ]]> Whereas this is valid, as the trailing newline after the switch statement is considered part of the closing ?> and hence nothing is output between the switch and case: ... ]]> See also while, for, and if for further examples.