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Home Backend Development PHP Tutorial class中$this->construct($x); 意思

class中$this->construct($x); 意思

Jun 20, 2016 pm 12:40 PM

class aaa{
var $b;
function __construct($x){
$this->b= $x;
}
    function b($x) {
     $this->__construct($x);
    }
function c{...}
function d(){...}
}

$k= new aaa(x);
$html_text = $k->d();

上面类里    的
function b($x) {
     $this->__construct($x);
    }
是怎么意思可以省略吗?谁能具体解释一下?


回复讨论(解决方案)

__construct 是构造函数
在 new classname 时被自动执行,主要的功能就是像你实例的那样做些初始化的工作
如果你没有什么事情要他做,自然就可以省略

function b($x) {
     $this->__construct($x);
    }


改成

function b($x) {
     $this->b=$x;
    }
你就明白了吧

__construct 构造函数
当类被实例化时自动调用. 通常用来初始化工作.

 更正一下
class里面的function b($x) {  $this->__construct($x); }这句原代码是这样的
function aaa($x) {  $this->__construct($x); }//更正一下 该函数名和class aaa名字相同   //只是这句不太理解,

我的理解是
在用$k= new aaa("x"); 实例化的时候会执行function __construct($x){$this->b= $x;} 从而完成赋值;
但class里面的其他的function c{...}和function d(){...}不会被执行,


那么问题是:
class里面的 唯一一个和class名称一样的function aaa且里面仅有一句话  $this->__construct($x); 起什么作用?
如果是在这个时候$k= new aaa("x");实例化就被执行了吗?
试了下好象没有被执行,因为我在里面加上echo "x"改成function aaa($x) {  $this->__construct($x);echo "aaaaa"; echo $x;}
$k= new aaa("x");后不会有输出;依然要在实例化后用$k->aaa(55555)才能输出
所以不明白和class里面同名称仅有 $this->__construct("实例化时的参数一样的参数")的vunction和什么特殊的作用?

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