Question

为什么我不能像这样在类属性中赋值？首先是我得到的错误：

解析错误：语法错误，第8行的C：\ wamp \ www \ site \ people.php中出现意外的'$ this'（T_VARIABLE）

代码：

$(document).ready(function () {

  $(".nav-basic").hover(function () {
      $('ul.menu-applied').slideUp('medium');   
      $('ul.menu-basic').slideDown('medium');
  });
  $('ul.menu-basic').bind('mouseleave', function(){
     $('ul.menu-basic').slideUp('medium'); 
  }); 

  $(".nav-applied").hover(function () {
      $('ul.menu-basic').slideUp('medium');     
      $('ul.menu-applied').slideDown('medium');
  });
  $('ul.menu-applied').bind('mouseleave', function(){
     $('ul.menu-applied').slideUp('medium'); 
  });


});

Answer 1

您不能在类属性中设置动态值;他们必须是不变的价值观。你必须在构造函数

中进行这样的赋值

// NO
private $person_info = $this->getName . ' ' . $this->getGender . ' and ' . $this->getAge() . '.';

// YES
public function __construct() {
  $this->person_info = $this->getName . ' ' . $this->getGender . ' and ' . $this->getAge() . '.';
}

但你真正的意思是这个

// you're calling get methods, not properties
// make sure to use $this->getName(), not $this->getName
public function __construct() {
  $this->person_info = $this->getName() . ' ' . $this->getGender() . ' and ' . $this->getAge() . '.';
}

但实际上你的所有代码都不好

// This makes no sense to have as a constant property in a class
private $person = array(
  'name' => 'Sarah',
  'gender' => 'female',
  'age' => 21
);

这个课程对你的目的更有意义

class Person { 

  // container for your info object
  private $info = [];

  // make info a parameter for your constructor
  public function __construct(array $info = []) {
    $this->info = $info;
  }

  // use PHP magic method __get to fetch values from info array
  public function __get(string $attr) {
    return array_key_exists($attr, $this->info)
      ? $this->info[$attr]
      : null;
  }

  // use PHP magic method __set to set values in the info array
  public function __set(string $attr, $value) {
    $this->info[$attr] = $value;
  }

  // single method to fetch the entire info object
  public function getInfo() {
    return $this->info;
  }
}

简单。让我们看看它现在如何运作

$p = new Person([
  'name' => 'Sarah',
  'gender' => 'female',
  'age' => 21
]);

echo $p->name, PHP_EOL;
// Sarah

echo $p->gender, PHP_EOL;
// female

echo $p->age, PHP_EOL;
// 21

echo json_encode($p->getInfo()), PHP_EOL;
// {"name":"Sarah","gender":"female","age":21}

因为$info数组现在是一个参数，所以您可以轻松地使用其他数据创建Person对象

$q = new Person([
  'name' => 'Joey',
  'gender' => 'male',
  'age' => 15
]);

echo $q->name, PHP_EOL;
// Joey

echo $q->gender, PHP_EOL;
// male

echo $q->age, PHP_EOL;
// 15

echo json_encode($q->getInfo()), PHP_EOL;
// {"name":"Joey","gender":"male","age":15}

PHP在类属性中分配连接方法

1 个答案: