What is meant by passing the variable by value and reference in PHP

Question

Explain me about the difference between passing the variable by value and reference with any sample code.

Thank you!!

Answer 1

Hello,

When the variable is passed as value then it is called pass variable by value.

Here, the main variable remains unchanged even when the passed variable changes.

Sample code:

function test($n) {
$n=$n+10;
}

$m=5;
test($m);
echo $m;

When the variable is passed as a reference then it is called pass variable by reference. 

Here, both the main variable and the passed variable share the same memory location and & is used for reference.

So, if one variable changes then the other will also change.

Sample code:

function test(&$n) {
    $n=$n+10;
}
$m=5;
test($m);
echo $m;

Thank You!