Question

我是愚蠢还是preg_match()不接受全局类变量？

class test{
    private$username,$usernameValidation;
    public function __construct($username){
        $this->username=$username;
        $this->usernameValidation="/^[a-zA-Z0-9]{0,8}$/";
    }
    public function validate(){
       if(!preg_match($this->usernameValidation,$this->username)){
           //failed;
       }
    }
}

每次我编译这样的函数时，它似乎告诉我表达式是空的。似乎工作为preg_match("/^[a-zA-Z0-9]{0,8}$/",$this->username);。

Answer 1

{,8}不是有效的重复，我想你想要：{0,8}或{8,}

Answer 2

您可以尝试在课程级别保留正则表达式分配：

class test {
    const UsernameValidation = '/^[a-zA-Z0-9]{0,8}$/';
    private $username;

    public function __construct($username){
        $this->username=$username;
    }
    public function validate(){
       if(!preg_match(UsernameValidation, $this->username)) {
           //failed;
       }
    }
}

Answer 3

您需要private和$username之间的空格，否则您将收到语法错误。此代码有效：

class test{
    private $username,$usernameValidation;
    public function __construct($username){
        $this->username=$username;
        $this->usernameValidation="/^[a-zA-Z0-9]{0,8}$/";
    }
    public function validate(){
        if(!preg_match($this->usernameValidation,$this->username)){
            echo 'failed';
        }
        else {
            echo 'matched';
        }
    }
}

$foo = new test('abcdefg');
$foo->validate();

Demo Link

preg_match不接受$ this

3 个答案: