PHP Basics 2

One, function assignment problem

    function Add ($num 1, $num 2=5) {        echo $num 1+ $num 2;    }    Add (5,19);

Second, global variables

• Add a variable to the global variable array
• When invoked: $GLOBALS [' global variable name '];
• In a function called global variables requested in the global, you want to use global declaration in the function, for example:
• Global $a;

Third, static variables

• A local variable is revoked when the function exits, but the static variable does not, and the value is preserved when the function is called again.
• static $a;

Iv. include, include_once, require, require_once

• Include: can make multiple calls, error, and then continue to execute.
• Include_once: can only be called once and is no longer executed if it has been previously called.
• Require: The difference from include in the event of an error will stop at the point of error.
• Require_once: The difference with include_once is that the error will stop.

PHP Basics 2