supposed i define a function like this:
function example(&node,$argument2,$argument3){
......
}
could i use this style to invoke the function.
1, example($node,$test1,$test2) //defined function's first argument is passed by reference. but the invoke function is not. could i use this?
2,example(&node,$test1,$test2,$test3,) .// defined function's parameter is three, here is four.could i use this?
1,
example($node,$test1,$test2);
This will still pass the first parameter by reference, because the function definition states so. You don't need to use any special syntax here.
So to answer the could I use it - Yes. That's actually how you should use it.
2,
example($node,$test1,$test2,$test3)
I assume this was a typo. The first parameter should still be noted as $node, not &node.
And it will still be passed as reference without any extra syntax.
The fourth parameter ($test3) will however be unknown within your original funciton. It will not have a name, because you didn't define the 4th param in you func declaration. In that case it will only be available as:
$test3 = func_get_arg(3);
If you want to pass any of the other parameters by reference, then you can use the special pass-by-ref on invocation syntax:
example($node, & $test1, & $test2);
This will give you an E_DEPRECATED warning on most setups. But it would still work as intended.
You only need the func( & $var ) syntax if you want to override what the function intended to be passed by reference per default.
You should use first call example($node,$test1,$test2)
call time pass by reference has been deprecated. so the second method will generate PHP warning message.
EDIT
See this question on SO PHP warning: Call-time pass-by-reference has been deprecated
you can use this
example($node,$test1,$test2)
but not point 2 because the number of parameters dont match...you can do that by function overloading
There's a native PHP function called func_get_args(). Here:
http://php.net/manual/en/function.func-get-args.php
That should do the trick.
IN PHP YOU WONT TO PASS BY reference
example(&$node,$test1,$test2,$test3,)
function add_some_extra(&$string)
{
$string .= 'and something extra.';
}
$str = 'This is a string, ';
add_some_extra($str);
echo $str; // outputs 'This is a string, and something extra.'
