Question

To indicate an argument is passed by reference to the function, what character should I use before the argument in the parenthesis??

I’m reading in one book:

When you use a function that passes an argument by reference, do not prefix the argument with an ampersand. The ampersand is used only in the function definition.

So what character is used? I’m just confused on this entirely.

Answer 1

As explained in the documentation, to define a function taking arguments by reference you prefix each such argument with &:

function getsArgumentByRef(&$argument) { /* ... */ }

When calling the function, do not use an ampersand:

$result = getsArgumentByRef($input);