这是使用构造函数初始化变量的正确方法吗?
class Customer
{
public $custId;
public $custName;
function _construct()
{
$this->custId = 'Eazy01';
$this->custName = 'EazyLearnKaloor';
}
function DisplayDetails()
{
echo "$custId<br>";
echo "$custName";
}
}
$obj = new Customer();
$obj->DisplayDetails();
您需要像在__construct()
中那样使用双下溢。
class Customer
{
public $custId;
public $custName;
function __construct()
{
$this->custId = 'Eazy01';
$this->custName = 'EazyLearnKaloor';
}
function DisplayDetails()
{
echo "$this->custId<br>"; // use $this here
echo "$this->custName"; // use $this here
}
}
$obj = new Customer();
$obj->DisplayDetails();
您还可以将变量传递给构造函数:
function __construct($id, $name)
{
$this->custId = $id;
$this->custName = $name;
}
然后在初始化新类时,您可以执行以下操作:
$var = new Customer('Eeazy01', 'EazyLearnKaloor');
imho正确的方式是
class Customer
{
public $custId;
public $custName;
// double underscores
function __construct($custId = 'Eazy01', $custName = 'EazyLearnKallor')
{
$this->custId = $custId;
$this->custName = $custName;
}
function DisplayDetails()
{
echo $this->custId . '<br />' . $this->custName;
}
}
$obj = new Customer();
$obj->DisplayDetails();
您需要使用双下划线:__construct
,当您想要打印变量时,必须使用$this->propertyName
。代码的其余部分是正确的。
class Customer
{
public $custId;
public $custName;
function _construct($custId = '', $custName = '')
{
$this->custId = $custId;
$this->custName = $custName;
}
function DisplayDetails()
{
$content = $this->custId . "<br />";
$content .= $this->custName;
echo $content;
}
}
$obj = new Customer();
$obj->DisplayDetails();
如果使用这种编码方式,就不必将参数传递给构造函数。您可以使用:
$obj = new Customer();
$obj->DisplayDetails();
和
$obj = new Customer('Hello', 'World');
$obj->DisplayDetails();
还有
$obj = new Customer(12);
$obj->DisplayDetails();
是。。。但是PHP中的构造函数名为__construct()
此外,您应该为属性使用Getters和Setters,并使它们受到保护或私有
在__construct()和$this
中使用双下划线在DisplayDetails
上"回显"参数
function DisplayDetails()
{
echo $this->custId, "<br>", $this->custName;
}
没有真正"正确"的方法,但它会很好地工作。通常,您将值传递给构造函数(注意双下划线):
function __construct($id, $name)
{
$this->custId = $id;
$this->custName = $name;
}
然后:
$obj = new Customer('Eazy01', 'EazyLearnKaloor');
此外,当你提到它们时,你需要在它们前面加上$this:
function DisplayDetails()
{
echo $this->custId . "<br>";
echo $this->custName;
}