如何在字符串中计算常量？

Question

  

可能重复：
  Include constant in string without concatenating

如何在变量的字符串中获得一个常量来计算？

$foo = "like";
define('BAR', 'fish');

// None of these give me 'I like to eat fish on Tuesday.'
echo "I $foo to eat BAR on Tuesday.";
echo "I $foo to eat {BAR} on Tuesday.";
echo 'I $foo to eat BAR on Tuesday.';

// This works but is undesirable
echo 'I $foo to eat '.BAR.' on Tuesday.';

Answer 1

我知道这种方法的唯一方法（你可能已经知道）是：

<?php
$foo = "like";
define('BAR', 'fish');
$constants = get_defined_constants();
echo "I $foo to eat {$constants['BAR']} on Tuesday.";
?>

打印：

I like to eat fish on Tuesday.

Answer 2

据我所知，这是不可能的。在SO处查看这个答案，它包含有用的解决方法，如果连接也是如此不受欢迎你！ Include constant in string without concatenating

Answer 3

当然没有办法。没有必要。