All Questions
Tagged with php-internals reference
8
questions
0
votes
0
answers
94
views
Adding new reference to any item in array affects behaviour of the array
I've seen many questions about this (one of them here)
$a = array('a', 'b', 'c', 'd');
foreach ($a as &$v) { }
foreach ($a as $v) { }
print_r($a);
and I get the answers, you shouldn't be ...
- 16
1
vote
0
answers
35
views
Are PHP zvals mutable?
I've been reading about memory management in PHP and learned that variables in PHP copy the reference to zvals as long as you don't do a write operation (copy on write paradigm).
https://www....
- 338
9
votes
2
answers
4k
views
Is there ever a need to use ampersand in front of an object?
Since objects are passed by reference by default now, is there maybe some special case when &$obj would make sense?
- 205
3
votes
1
answer
167
views
PHP ignoring returned reference from function considered harmful?
Derick Rethans has an old article that says:
Please do note that it is harmful not to accept a reference from a
function that returns a reference. In some cases, PHP will get
confused and cause ...
- 88.6k
2
votes
1
answer
254
views
Why does a PHP array get modified when it's element is reference-assigned?
When ref-assigning an array's element, the contents of the array are modified:
$arr = array(100, 200);
var_dump($arr);
/* shows:
array(2) {
[0]=>
int(100) // ← ← ← int(100)
[1]=>
int(...
- 88.6k
1
vote
1
answer
107
views
Why C.O.W does not take place when ' writing to a property ' / ' injecting a property into an object ' of class?
class a {
public $test="msg1";
}
$t1 = new a;
echo "echo1: After Instantiation :<br/>";
xdebug_debug_zval('t1');echo "<br/><br/>";
$t2 = $t1;
echo 'echo2: After ...
- 12.7k
17
votes
2
answers
478
views
What is exactly happening when instantiating with 'new'?
Let's consider the following code:
class a {
public $var1;
function disp(){
echo $this->var1;
}
}
$obj1 = new a;
echo '<br/>After instantiation into $obj1:&...
- 12.7k
8
votes
6
answers
4k
views
PHP Performance : Copy vs. Reference
Hey there. Today I wrote a small benchmark script to compare performance of copying variables vs. creating references to them. I was expecting, that creating references to large arrays for example ...
- 25.7k