current() advances untouched generator, same as next(), it makes the first step/iteration. the following calls will not.
non-yielded value will be NULL
(PHP 5 >= 5.5.0, PHP 7, PHP 8)
Generator::current — 返回当前产生的值
此函数没有参数。
返回当前产生的值。
current() advances untouched generator, same as next(), it makes the first step/iteration. the following calls will not.
non-yielded value will be NULL