php:函数间的参数传递
1.值传递
<?php function exam($var1){ $var1++; echo "In Exam:" . $var1 . "<br />"; } $var1 = 1; echo $var1 . "<br />"; exam($var1); echo $var1 . "<br />"; ?>
-------------------------------------------------------------------------------
输出结果:
1
In Exam: 2
1
-------------------------------------------------------------------------------
2.引用传递
<?php function exam( &$var1){ $var1++; echo "In Exam:" . $var1 . "<br />"; } $var1 = 1; echo $var1 . "<br />"; exam($var1); echo $var1 . "<br />"; ?>
-------------------------------------------------------------------------------
输出结果:
1
In Exam: 2
2
-------------------------------------------------------------------------------
3.可选参数
function values($price, $tax=""){ $price += $prive * $tax; echo "Total Price:" . $price . "<br />"; } values(100, 0.25); values(100);
输出结果:
Total Price: 125
Total Price: 100
-------------------------------------------------------------------------------
4.如果传入的是一个对象,可以更改该对象的值
(实际上变量$obj记录的是这个对象的句柄,将$obj作为参数传入,完全可以对原对象进行操作。)
<?php class Obj{ public $name; public $age; public $gander; public function construct($name, $age, $gander){ $this->name = $name; $this->age = $age; $this->gander = $gander; } public function show_info(){ echo $this->name . " " . $this->age . " " . $this->gander . "<br />"; } } function grow($obj){ $obj->age++; } function test(){ $obj = new Obj("Mr. zhan", "12", "male"); $obj->show_info(); grow($obj); $obj->show_info(); grow($obj); $obj->show_info(); } test(); ?>
-------------------------------------------------------------------------------
输出结果:
Mr. zhan 12 male
Mr. zhan 13 male
Mr. zhan 14 male
Atas ialah kandungan terperinci php自定义函数间的值传递/引用传递用法详解. Untuk maklumat lanjut, sila ikut artikel berkaitan lain di laman web China PHP!