PHP create_function与嵌套数组 [英] PHP create_function with nested arrays

问题描述

我需要使用create_function，因为运行应用程序的服务器上的PHP版本已经过时.

I need to use create_function because the server the application is running on has an outdated version of PHP.

问题是我传递到usort的项目是数组，我需要按数组中的值排序:

The issue is that the items I pass into usort are arrays and I need to sort by a value within the array:

$sort_dist = create_function( '$a, $b', "
    if( $a['order-dir'] == 'asc' ) {
        return $a['distance'] > $b['distance'];
    }
    else {
        return $a['distance'] < $b['distance'];
    }" 
);

usort( $items, $sort_dist );

给出错误:syntax error, unexpected T_ENCAPSED_AND_WHITESPACE, expecting T_STRING or T_VARIABLE or T_NUM_STRING

删除对['distance']和['order-dir']的引用将消除此错误.

Removing the references to ['distance'] and ['order-dir'] removes this error.

有人知道如何将create_function与嵌套数组一起使用吗?

Does anyone know how to use create_function with nested arrays?

推荐答案

您需要转义变量名.根据 create_function 文档(重点是我):

You need to escape your variable names. Per the create_function documentation (emphasis mine):

通常，这些参数将作为单引号分隔的字符串传递.使用单引号引起来的字符串的原因是为了保护变量名免于解析，否则，如果使用双引号，则需要转义变量名，例如\$avar .

我应该为以后的读者指出，范坎彭的答案可能是您应该使用的解决方案，但如果您绝对使用需要使用create_function，我的答案应该起作用.

I should note for future readers that Frits van Campen's answer is probably the solution you should use, but if you absolutely need to use create_function, my answer should work.

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