difference between function and &function [duplica

Question

This question already has answers here:

What does it mean to start a PHP function with an ampersand? (3 answers)

Reference — What does this symbol mean in PHP? (18 answers)

Closed 4 years ago.

function fun1();
function &fun1();

What is the difference between these??

Answer 1

If you put an ampersand before your function name, the function will return a reference to a variable instead of the value.

Returning by reference is useful when you want to use a function to find to which variable a reference should be bound. Do not use return-by-reference to increase performance. The engine will automatically optimize this on its own. Only return references when you have a valid technical reason to do so.

From the PHP Manual on Returning References.

Answer 2

The difference is how the return value is returned: Without & the return value is returned by value and with & the return value is returned by reference.

The latter implies that you need to use a variable in the return statement as you can only reference variables.