具有默认值的私有类变量 - 语法错误

Question

有人可以告诉我我做错了什么。想要用一些带有默认值的私有变量声明我的类，但是在声明$ current_week_day时我出现语法错误，并且每次尝试声明名称＆＃39;和＆＃39; date＆＃39;属性。

class Catwz_Shortcode{
    private $add_script=false;

    private $current_week_day=date('w')==0 ? 7 : date('w');
    private $week_days=array(
        '1'=>array(
            'name'=>__('Monday', 'codeaddict-task'),
            'date'=>date('Y-m-d',time()+(1-$this->current_week_day)*24*3600),
        ),
        '2'=>array(
            'name'=>__('Tuesday', 'codeaddict-task'),
            'date'=>date('Y-m-d',time()+(2-$this->current_week_day)*24*3600),
        ),
        '3'=>array(
            'name'=>__('Wednesday', 'codeaddict-task'),
            'date'=>date('Y-m-d',time()+(3-$this->current_week_day)*24*3600),
        ),
        '4'=>array(
            'name'=>__('Thursday', 'codeaddict-task'),
            'date'=>date('Y-m-d',time()+(4-$this->current_week_day)*24*3600),
        ),
        '5'=>array(
            'name'=>__('Friday', 'codeaddict-task'),
            'date'=>date('Y-m-d',time()+(5-$this->current_week_day)*24*3600),
        ),
        '6'=>array(
            'name'=>__('Saturday', 'codeaddict-task'),
            'date'=>date('Y-m-d',time()+(6-$this->current_week_day)*24*3600),
        ),
        '7'=>array(
            'name'=>__('Sunday', 'codeaddict-task'),
            'date'=>date('Y-m-d',time()+(7-$this->current_week_day)*24*3600),
        ),
    );
}