html&php Study notes (2)

PHP tagged <?php?>

Semicolon-delimited statement.

HTML PHP ignores interval characters (carriage return, space, TAB)

Multiline Comment:/* */

Single-line Comment: #//

Connection operator (.)

form variables

$_post[' var '] $_get[' var '] $_request[' var '//Super global variable

Double quotes can refer to the variable echo "$var <br/>"; Single quotes are not allowed

The single-quote string is treated as true text, and PHP tries to calculate the double-quote string

Identifiers cannot start with numbers and are case-sensitive.

Variable variable:

$b = ' a ';

$ $b = 1;

A = 1

Declare constant define (' XXX ', 10); Reference constants do not require $

Reference Operators &

1 $a = 5; 2 $b $a ; 3 $a // $b = 5 4 5 $b = &$a; 6 $a = 7;  // $b = 7

unset ($a); Reset

To set the variable type:

GetType ($a);

Settype ($a, ' double ');

html&php Study notes (2)