PHP learning Notes (1): Mark, blank, and comment of basic syntax; learning notes basic syntax _ PHP Tutorial

PHP learning Notes (1): Mark, blank, and comment of basic syntax, and learn the basic syntax of notes. PHP learning Notes (1): Mark, blank, and comment of basic syntax; basic syntax of learning Notes 1. PHP markup 1. code for copying XML styles: phpechohelloworld; 2. PHP learning Notes (1): Mark, blank, and comment of basic syntax, and learn the basic syntax of notes

I. PHP mark

1. XML style
The code is as follows:
<? Php echo "hello world";?>

2. short style
The code is as follows:
<? Echo "hello world";?>

3. script style
The code is as follows: