具有三个可选参数但需要一个参数的 PHP 类构造？
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PHP Class construct with three optional parameters but one required?
提问by farinspace
So basically I understand this ...
所以基本上我明白这一点......
class User
{
function __construct($id) {}
}
$u = new User(); // PHP would NOT allow this
I want to be able to do a user look up with any of the following parameters, but at least one is required, while keeping the default error handling PHP provides if no parameter is passed ...
我希望能够使用以下任何参数进行用户查找，但至少需要一个参数，同时保持 PHP 提供的默认错误处理（如果没有传递参数）...
class User
{
function __construct($id=FALSE,$email=FALSE,$username=FALSE) {}
}
$u = new User(); // PHP would allow this
Is there a way to do this?
有没有办法做到这一点？
回答by Gumbo
You could use an array to address a specific parameter:
您可以使用数组来寻址特定参数：
function __construct($param) {
$id = null;
$email = null;
$username = null;
if (is_int($param)) {
// numerical ID was given
$id = $param;
} elseif (is_array($param)) {
if (isset($param['id'])) {
$id = $param['id'];
}
if (isset($param['email'])) {
$email = $param['email'];
}
if (isset($param['username'])) {
$username = $param['username'];
}
}
}
And how you can use this:
以及如何使用它：
// ID
new User(12345);
// email
new User(array('email'=>'[email protected]'));
// username
new User(array('username'=>'John Doe'));
// multiple
new User(array('username'=>'John Doe', 'email'=>'[email protected]'));
