Side Effect in PHP

[Xelene]

Try this.

$x['foo'] = 'foo';
$x['foo']['bar'] = 'bar';
var_dump($x);

 

[fez]

Yeah, php is a pretty dirty language at times. It will try its best to cover for huge blunders but in doing so doesn't always come up with the correct answer. Have to admit though, that is a doozie.

 

[FragnaticDeath]

$x['foo'][] = 'bar'; 
$x['foo']['bar'] = 'bar';
var_dump($x);

hmmmm that is weird.... :/

 

[GravyMonster]

For those of us who don't frequent the PHP world, what happens?

My guess would be that it joins the array?

*edit*
Just tried it in an online editor. It's little like how in C# if you print an object to the screen you get the namespace of that object.

 

[namnoc]

It makes perfect sense.

First you set set the element 'foo' to equal "foo"

Then you try to set one character of that element. 'bar' isn't defined as as integer so is taken as 0 and the first character of "bar" is used as you are only setting one character.

 

[Xelene]

It makes sense once you realize what's going on, but it's messy.

$x['foo'] = 'foo';

As $x is uninitialized, the parser reads the [] as an array access and creates an $x as array of 'foo' => 'bar'

$x['foo']['bar'] = 'bar';

$x is now initialized as an array but $x['foo'] is a string within that array so the second set of brackets treated as (rarely) used string accessors. 'bar' is a string that is silently casted to 0 as that is what the string accessor expects and the value of the first character $x['foo'] is set to 'b' (as a range wasn't specified).

It's an odd one, because you'd normally expect the code:

$x['foo']['bar'] = 'bar';

To set a $x -> child_element (foo) -> child_element (bar) to bar. The correct code is actually:

$x = array('foo'=>'foo');
$x['foo'] = array('bar'=>'bar');

(The original value of $x['foo'] gets clobbered)