Question

As PHP borrows most of its object oriented features from java. I would like to know whether PHP and java both uses the same concept of pass by value?

I know Java is not pass by reference.Its just that object references are passed by value. How about PHP? Does PHP support pass by reference?

Answer 1

In PHP, you only pass stuff by reference if you declare a function and litter it with ampersands:

function &return_by_reference() {
    $something = make_something();
    return $something;
}

function increment(&$n) {
    // This changes $n because it is a reference parameter
    $n++;
}

There is call-time pass-by-reference as well (i.e. passing variables by reference when you call functions), but I shan’t go on about it because it presents a risk for unexpected behavior. It’s better practice to declare parameters to be passed by reference in your function signatures instead.

As for objects: in PHP 4, objects are all passed by value. In PHP 5, references to objects are passed by value, just like in Java.