Difference between heredoc and nowdoc

Introduction

In this article I will explain the difference between Heredoc and Nowdoc in PHP. Heredoc and Nowdoc are two methods for defining a string. A third and fourth way to delimit strings are the Heredoc and Nowdoc; Heredoc processes $variable and special character but Nowdoc does not processes a variable and special characters. First of all I will discuss Heredoc.

Heredoc allows a multi-line string to be easily assigned to variables or echoed. Heredoc text behaves just like a string without the double quotes.

Example

The following is a simple example of Heredoc:

<?php
class ABC
{
    public $ABC;
    public $bar;
    function ABC()
    {
        $this->ABC = 'ABC';
        $this->bar = array('Bar1', 'Bar2', 'Bar3');
    }
}
$ABC = new ABC();
$name = 'Tom';
echo <<<EOT
My name is "$name". I am printing some $ABC->ABC.
Now, I am printing some {$ABC->bar[1]}.
This should not print a capital 'A': \x41
EOT;
?>

OutPut:

Next, I will discuss Nowdoc. Nowdoc is an identifier with a single quote string and Nowdoc is specified similarly to a Heredoc but no parsing is done inside a Nowdoc. A Nowdoc is identified with the same "<<<" sequence used for heredoc. When you use Nowdoc then you cannot pass the space character.

Note Nowdoc is supported only PHP 5.3

Example

<?php
class ABC
{
    public $ABC;
    public $bar;
    function ABC()
    {
        $this->ABC = 'ABC';
        $this->bar = array('Bar1', 'Bar2', 'Bar3');
    }
}
$ABC = new ABC();
$name = 'Tom';
echo <<<'EOT'
My name is "$name". I am printing some $ABC->ABC.
Now, I am printing some {$ABC->bar[1]}.
This should not print a capital 'A': \x41
EOT;
?>
OutPut: