PHP Heredoc and Nowdoc

PHP Heredoc and Nowdoc

Heredoc structure

HEREDOC syntactic structure:<<<. After the operator, provide an identifier, and then wrap the line. The next is the string itself, and finally the identifier defined earlier as the end flag.

<?php$content = <<<FDIPZONE
The HEREDOC structure cannot be used to initialize the properties of a class. Since PHP 5.3, this limit is only valid for Heredoc including variables. The following example will cause an error.
<?phpclass test{public $var = ' 123 ';p ublic $a = <<<fdipzone$varfdipzone;} $obj = new test (); Echo $obj->a;? >
In the HEREDOC structure, the variable is replaced, but the method does not. Take extra care when you have complex variables.
<?php$var = ' 123 '; $content = <<<fdipzone$var time (); Fdipzone;echo $content; 123 time ();? >

Nowdoc Structure
The syntactic structure of nowdoc is very much like the heredoc structure, but the parsing operation is not performed in Nowdoc. Such a structure is ideal for embedding PHP code or other large pieces of text without escaping special characters.
Nowdoc the same tag <<< as the HEREDOC structure, but the following identifiers must be enclosed in a single argument , <<< ' EOF '. The full rules of the HEREDOC structure are the same for nowdoc structures, especially the rules for ending identifiers. Nowdoc was added after the php5.3.
<?php$var = ' 123 '; $content = <<< ' Fdipzone ' $var time (); Fdipzone;echo $content; $var time (); $var have not been replaced?>
The NOWDOC structure can be used in a casual, static data environment, and the most typical demo sample is a property or constant used to initialize a class. The following example will not be error-able to control the Heredoc sample.
<?phpclass test{public $a = <<< ' Fdipzone ' $varFDIPZONE;} $obj = new test (); Echo $obj->a;? >