php函数间的参数传递(值传递/引用传递)

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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

参数传递

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