PHP数组按位
问题描述：
如果我有标志的数组，我想他们按位一起结合
if I have an array of flags and I want to combine them with a bitwise conjunction
例如：
$foo = array(flag1, flag2);
到
$bar = flag1 | flag2;
PHP是否有什么好的功能，将做到这很好地为我了吗？
Does PHP have any good functions that will do this nicely for me already?
答
The array_reduce will reduce an array to a single value for you:
$res = array_reduce($array, function($a, $b) { return $a | $b; }, 0);
减少有时也被称为折（折向左或向右折叠）的其他语言。
Reduce is also sometimes called fold (fold left or fold right) in other languages.