我们可以使用EOF多少次？

Question

I was used EOF for print html code in PHP . for example :

echo <<<EOF
    Hello World!
EOF;

What volume of output can be used for eof ?
How many times can we use EOF ?

Answer 1

The technical name for this syntax is Heredoc .

The PHP documentation doesn't specify a maximum length of content, however you would foolish to use it for very large amounts of text/HTML etc. as it makes your code unreadable and harder to maintain.

Example: If you have an HTML page which needs some customisation, far better to code the whole thing as a normal HTML file and add <?php echo "Hello World!"; ?> <?php echo "Hello World!"; ?> in the appropriate place. (This is how views in model-view-controller (MVC) work.)

You can use heredoc multiple times and with an identifier other than EOF .