为什么在array_slice中有一个＆before $输入（数组和$ input，int $ offset [，int $ length = 0 [，mixed $ replacement]]）

Question

array array_splice  ( array &$input  , int $offset  [, int $length = 0  [, mixed $replacement  ]] )

Why is there an & before $input?

Answer 1

That means the $input array is passed by reference, so any changes made in the function affect that array. The default behaviour is to pass a copy, so changes made inside the function don't affect the original.