Question

当我在php类中定义私有变量时使用count时，它会抛出错误。这是我的班级

class setup {

private $acctListArr = array(4533,4534,4535,4536,4537,4538,4539,4540,4541,4542,4543,4544,4545,4546,4547,4548,4549,4550,4551,4552,4553,4554,4555,4556,4557,4559,4560,4561,4562,4563,4564,4565,4566,4567,4568,4569,4570,4571,4572,4573,4574,4575,45766,4577,4578,4579,4580,4581,4582,4583,4584,4585,4586,4587,4588,4589,4590,4591,4592,4593,4594,4595,4596,4597,4598,4599,4600,4601,4602,4603,4604,4605,4606,4607,4608,4609,4610,4611,4612,4613,4614,4615,4616,4617,4618);
private $acctsInList = count($this->acctListArr);

public function __construct() {
}

}

在浏览器中访问该类时会抛出错误：

解析错误：第7行的C：\ xampp \ htdocs \ dev.virtualnerd.com_classes \ setup.class.php中的语法错误，意外'（'，期待'，'或';'

第7行为private $acctsInList = count($this->acctListArr);

你能否以这种方式定义私有变量？

Answer 1

不，你不能。无法使用计算值（例如，函数调用）定义类属性。

来自the docs：

此声明可能包括初始化，但此初始化必须是常量值 - 也就是说，它必须能够在编译时进行评估，并且必须不依赖于运行时信息才能进行评估。

正如其他人所指出的那样，你可以改为进行计算并在构造函数中指定它。

Answer 2

您无法在实例变量的声明中调用函数。而是在构造函数中指定它，如下所示：

 private $acctListArr = array(4533,4534,4535,4536,4537,4538,4539,4540,4541,4542,4543,4544,4545,4546,4547,4548,4549,4550,4551,4552,4553,4554,4555,4556,4557,4559,4560,4561,4562,4563,4564,4565,4566,4567,4568,4569,4570,4571,4572,4573,4574,4575,45766,4577,4578,4579,4580,4581,4582,4583,4584,4585,4586,4587,4588,4589,4590,4591,4592,4593,4594,4595,4596,4597,4598,4599,4600,4601,4602,4603,4604,4605,4606,4607,4608,4609,4610,4611,4612,4613,4614,4615,4616,4617,4618);

 private $acctsInList;

 public function __construct() {
     $this->acctsInList = count($this->acctListArr);
 }

Answer 3

你想要的是

class setup {

private $acctListArr = array(4533,4534,4535,4536,4537,4538,4539,4540,4541,4542,4543,4544,4545,4546,4547,4548,4549,4550,4551,4552,4553,4554,4555,4556,4557,4559,4560,4561,4562,4563,4564,4565,4566,4567,4568,4569,4570,4571,4572,4573,4574,4575,45766,4577,4578,4579,4580,4581,4582,4583,4584,4585,4586,4587,4588,4589,4590,4591,4592,4593,4594,4595,4596,4597,4598,4599,4600,4601,4602,4603,4604,4605,4606,4607,4608,4609,4610,4611,4612,4613,4614,4615,4616,4617,4618);

private $acctsInList = 0;

public function __construct() {
  $this->acctsInList = count($this->acctListArr);
}


}

Answer 4

您可以像这样编写类

class setup {

    private $acctListArr = array(4533,4534,4535,4536,4537,4538,4539,4540,4541,4542,4543,4544,4545,4546,4547,4548,4549,4550,4551,4552,4553,4554,4555,4556,4557,4559,4560,4561,4562,4563,4564,4565,4566,4567,4568,4569,4570,4571,4572,4573,4574,4575,45766,4577,4578,4579,4580,4581,4582,4583,4584,4585,4586,4587,4588,4589,4590,4591,4592,4593,4594,4595,4596,4597,4598,4599,4600,4601,4602,4603,4604,4605,4606,4607,4608,4609,4610,4611,4612,4613,4614,4615,4616,4617,4618);

    private $acctsInList = 0;

    public function __construct() {
        $this->acctsInList = count($this->acctListArr);
    }
}

在私有类成员定义中使用count（）会导致Parse错误

4 个答案: