Question

所以我有一个问题我有一个传递给setData函数的数组之后我调用getE来假设返回数组但是我得到Null我做错了什么？

<?php

class Se {      
    public $data1; 

    public function setData(array $data){
        if (empty($data)) {
        throw new InvalidArgumentException('The name of an employee cannot be empty.');
     }

    $data1 = $data;
        $data1 =  array_values($data1);
        var_dump($data1);   
    }


    public function getE(){ 
        return $data1[0];
    }
}

$tmpaaa= array('3333','222');
$ttt = new Se();
$ttt->setData($tmpaaa);

echo $ttt->getE();

所以我修改后的代码现在看起来像这样

class Se {

    public $data1; 

public function setData(array $data)
{

if (empty($data)) 
{
throw new InvalidArgumentException('The name of an employee cannot be empty.');
 }
     $this->data1 = $data;     

}


    public function getE()
{   
return $this->$data1[0];

}



 };
$tmpaaa= array('3','2');
 $ttt = new Se();
$ttt->setData($tmpaaa);
echo $ttt->getE();
 ?>

Answer 1

为了从类中访问类实例属性，您需要在变量名前加$this。见http://php.net/manual/language.oop5.properties.php

要解决您的问题，请在setData

中进行更改

$data1 = $data;
$data1 =  array_values($data1);
var_dump($data1);

到这个

$this->data1 = array_values($data);
var_dump($this->data1);

和getE到

public function getE(){ 
    return $this->data1[0];
}

更新

因为$data1中需要Se属性，我会在构造函数中设置它，例如

public function __construct(array $data) {
    $this->setData($data);
}

并使用

实例化它

$ttt = new Se($tmpaaa);
echo $ttt->getE();

Answer 2

还建议不要关闭类文件中的php标记，这样可以防止空间问题。

<?php
class Se {      

    public $data1; 

    public function setData(array $data)
    {
        if (empty($data)) 
        {
            throw new InvalidArgumentException('The name of an employee cannot be empty.');
        }

        $this->data1 = array_values($data);  //you error was here, no need to to assign $data twice so I deleted top line.
    }


    public function getE()
    { 
        return $this->data1[0];

    }
}

$tmpaaa = array('3333','222');
$ttt = new Se();
$ttt->setData($tmpaaa);

echo $ttt->getE();

传递给函数后，PHP数组为null

2 个答案:

更新