Function and Class Syntax

PHP
Function Example	function inc($val) { return $val + 1;} Procedures are functions that return no value.
Class Example	class parent { var property; function parent() { } function method() { } } /* inheritance */ class child extends parent { var property='new value'; }
Scope of Variables	Variables defined outside a function or class are available globally; variables defined in a class or function are available locally.Unlike other languages, you must declare a global variable in a function or class before you use the variable, using the keyword global. $globalvar = 1; function show_global( ) { global $globalvar; print $globalvar; }
Call by Reference	Use & keyword in function parameters.
Default Parameters	Yes.function A(param1=”abc”)
Returning by Reference	By default, return is by value. For objects and arrays, we want to return by reference for superior performance. Use function & getarray123() { $val = array(1,2,3); return $val; } Then in the calling code, use $val = &getarray123();