PHP:即时访问数组值 [英] PHP: Access Array Value on the Fly

问题描述

在 php 中，我经常需要使用数组来映射变量......但我似乎无法在一个班轮中做到这一点.比照例子:

In php, I often need to map a variable using an array ... but I can not seem to be able to do this in a one liner. c.f. example:

// the following results in an error:
echo array('a','b','c')[$key];

// this works, using an unnecessary variable:
$variable = array('a','b','c');
echo $variable[$key];

这是一个小问题，但它每隔一段时间就会被窃听......我不喜欢这样一个事实，即我不使用变量;)

This is a minor problem, but it keeps bugging every once in a while ... I don't like the fact, that I use a variable for nothing ;)

推荐答案

我不会为那个额外的变量而烦恼，真的.不过，如果您愿意，也可以在使用后将其从内存中删除:

I wouldn't bother about that extra variable, really. If you want, though, you could also remove it from memory after you've used it:

$variable = array('a','b','c');
echo $variable[$key];
unset($variable);

或者，你可以写一个小函数:

Or, you could write a small function:

function indexonce(&$ar, $index) {
  return $ar[$index];
}

并调用它:

$something = indexonce(array('a', 'b', 'c'), 2);

现在应该自动销毁数组.

The array should be destroyed automatically now.

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