Question

例如我在课堂上有这个：

private $messages = array( 
    'name'=>        '<aa_f>name',
    'PASS' =>       '<aa_p>'
);

但我想让<aa_p>变成这样的变量：

private $pass = '<aa_p>';

我尝试了这4种方法，但都没有效果。 PHP.net没有这样做的例子。

    'PASS' =>       $this->pass
    'PASS' =>       $pass
    'PASS' =>       '$this->pass'
    'PASS' =>       '$pass'

完整代码

<?php
class Message
{
    private $PASS = '<aa_p>';
    private $FAIL = '<aa_f>';

    private $messages = array( 
        'name'=>        '<aa_f>name',
        'email' =>      '<aa_f>email_s', 
        'pass' =>       '<aa_f>pass',
        'url' =>        '<aa_f>url',
        'title' =>      '<aa_f>title',
        'tweet'=>       '<aa_f>tweet',
        'empty' =>      '<aa_f>empty', 
        'same' =>       '<aa_f>same',  
        'taken' =>      '<aa_f>taken', 
        'validate' =>   '<aa_f>validate',
        'PASS' =>       '<aa_p>'
    );
    public function __construct()
    {
    }
    public function display($type)
    {
        echo $this->messages[$type];
    }
    public function get($type)
    {
        return $this->messages[$type];
    }
}

更新：回答

供参考:(更新代码）

class Message
{
    private $PASS = '<aa_p';
    private $FAIL = '<aa_f>';
    private $messages = array();

    public function __construct()
    {
        $this->messages['PASS'] = $this->PASS;
        $this->messages['name'] = $this->FAIL . 'name';
        $this->messages['email'] = $this->FAIL . 'email_s';
        $this->messages['pass'] = $this->FAIL . 'pass';
        $this->messages['url'] = $this->FAIL . 'url';
        $this->messages['title'] = $this->FAIL . 'title';
        $this->messages['tweet'] = $this->FAIL . 'tweet';
        $this->messages['empty'] = $this->FAIL . 'empty';
        $this->messages['same'] = $this->FAIL . 'same';
        $this->messages['taken'] = $this->FAIL . 'taken';
        $this->messages['validate'] = $this->FAIL . 'validate';
    }
    public function display($type)
    {
        echo $this->messages[$type];
    }
    public function get($type)
    {
        return $this->messages[$type];
    }
}

Answer 1

如果你的意思是你有这样的东西：

class Test {
    private $pass = '<aa_p>';
    private $messages = array(
        'name' => '...',
        'PASS' => '...'
    );
}

并且您希望将'PASS'设置为私有$pass属性的值，然后您无法在定义中执行此操作，因为PHP语法不允许它。您必须在可以评估表达式的地方执行此操作，例如在方法中。构造函数将是一个很好的地方：

class Test {
    private $pass = '<aa_p>';
    private $messages = array(
        'name' => '...'
    );

    public function __construct() {
        $this->messages['PASS'] = $this->pass;
    }
}

Answer 2

您需要在构造函数中设置变量。在构造函数之外，您无法读取其他变量。

class Message{
    private $PASS = '<aa_p>';
    private $messages = array();

    public function __construct(){
        $this->messages['PASS'] = $this->PASS;
    }
}

Answer 3

只有在编译时可以确定的值才可用于启动类成员。您需要在运行时设置值（通过构造函数）：

class Message
{
    private $PASS = '<aa_p';
    private $FAIL = '<aa_f>';

    private $messages = array( 
        'name'=>        '<aa_f>name',
        'email' =>      '<aa_f>email_s', 
        'pass' =>       '<aa_f>pass',
        'url' =>        '<aa_f>url',
        'title' =>      '<aa_f>title',
        'tweet'=>       '<aa_f>tweet',
        'empty' =>      '<aa_f>empty', 
        'same' =>       '<aa_f>same',  
        'taken' =>      '<aa_f>taken', 
        'validate' =>   '<aa_f>validate',
        'PASS' =>       null
    );


    public function __construct()
    {
        $this->messages['PASS'] = $this->PASS;
    }

}

在数组中，如何使值（在键/值对中）等于变量？

3 个答案: