php函数间的参数传递(值传递/引用传递)

发布时间：2020-12-12 19:54:26 所属栏目：PHP教程来源：网络整理

导读：php:函数间的参数传递 1.值传递 div class="codetitle" a style="CURSOR: pointer" data="9867" class="copybut" id="copybut9867" onclick="doCopy('code9867')" 代码如下: div class="codebody" id="code9867" ?php function exam($var1){ $var1++； echo

php:函数间的参数传递

1.值传递

<div class="codetitle"><a style="CURSOR: pointer" data="9867" class="copybut" id="copybut9867" onclick="doCopy('code9867')"> 代码如下:<div class="codebody" id="code9867">
<?php
function exam($var1){
$var1++；
echo "In Exam:" . $var1 . "
";
} $var1 = 1;
echo $var1 . "
";
exam($var1);
echo $var1 . "
";
?>

-------------------------------------------------------------------------------
输出结果：
1
In Exam: 2
1
-------------------------------------------------------------------------------

2.引用传递

<div class="codetitle"><a style="CURSOR: pointer" data="1581" class="copybut" id="copybut1581" onclick="doCopy('code1581')"> 代码如下:<div class="codebody" id="code1581">
<?php
function exam( &$var1){
$var1++；
echo "In Exam:" . $var1 . "
";
} $var1 = 1;
echo $var1 . "
";
exam($var1);
echo $var1 . "
";
?>
-------------------------------------------------------------------------------
输出结果：
1
In Exam: 2
2
-------------------------------------------------------------------------------

3.可选参数

<div class="codetitle"><a style="CURSOR: pointer" data="79555" class="copybut" id="copybut79555" onclick="doCopy('code79555')"> 代码如下:<div class="codebody" id="code79555">
function values($price,$tax=""){
$price += $prive * $tax;
echo "Total Price:" . $price . "
";
} 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。）
<div class="codetitle"><a style="CURSOR: pointer" data="19076" class="copybut" id="copybut19076" onclick="doCopy('code19076')"> 代码如下:<div class="codebody" id="code19076">
<?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 . " " . $this->gander . "
";
}
}
function grow($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

（编辑：李大同）

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