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Home Backend Development PHP Tutorial PHP能不能实现这样的函数代码?

PHP能不能实现这样的函数代码?

Jun 06, 2016 pm 08:30 PM
php

<code>
function a($b){
    代码......
    
    这里面有一个给数组赋值的代码.....
}


a('b') = 'c';
?>
</code>
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回复内容:

<code>
function a($b){
    代码......
    
    这里面有一个给数组赋值的代码.....
}


a('b') = 'c';
?>
</code>
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简单而言是不能的。
会报错:Fatal error: Can't use function return value in write context in /in/R5ZEN on line 10
代码和运行结果参见这里:http://3v4l.org/R5ZEN

看了下评论,LZ似乎是不想a('b','c')这样写。其实是有另外一种类似的方法来解决这个问题的 —— ArrayAccess.
比如Yii框架中的CCache就实现了ArrayAccess,以前设置缓存只能$cache->set('some-key', $someValue),现在就可以用$cache['some-key'] = $someValue,多方便。具体代码参考这里:http://phpcrossref.com/xref/yii/framework/caching/CCache.php.html#offs...

可以使用PHP来解析这段自定义语法.
其实题主的意思就是: 将a方法中的变量b的值修改为c
这样就很容易了, 使用正则或者自己写语法分析(题主需要的话再补)
解析的结果为:

<code>#! /usr/bin/env php
<?php function a($arr){
    if($arr[0] == 'b'){
        $b = $arr[1];
        print $b;
    }
}

# 使用此方法解析自定义的语法, 伪代码需要再补
function exec_str($str){
    $func = 'a';
    $b = array('b', 'c');
    $func($b);
}

# 自定义代码
$str = "a('b') = 'c'";

# 执行自定义代码
exec_str($str);
</code></code>
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试试 call_user_func 能满足要求不?

http://php.net/manual/zh/function.call-user-func.php

<code>function a ($b) {
    if ($b == 'b') {
        return 'c';
    }
}
var_dump(a('b')); //结果:'c'
</code>
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不是很理解你的意思,是指a函数,输入参数:'b',结果就等于'c'么?

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