which is slower? error suppressing or a dedicated function?

Take this:

$data = array('one'=>'1','three'=>'3');

Now which is better? This:

echo @$data['two'];

or this:

function val($data,$key,$default){
  if(isset($data[$key])){
    return $data[$key];
  }
  return $default;
}
echo val($data,'two','');

or this:

echo isset($data['two'])?$data['two']:'';

or something else?

avoiding the notice: Notice: Undefined index: two in document on line #num

which one is the most efficient, and which one should I use? I am wondering that maybe the super-slow error suppressing might be faster than having a dedicated function?

p.s. Lots of answers seem to assume that I am doing this as a form of optimization, this is not true, I am asking the "efficiency" part out of curiosit开发者_如何学编程y and the "which should I use" part because I need to use something and I want to know what I should default to.

p.p.s. most efficient and which used will most likely be different

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Use whichever you like best. The slowness of your application does not come from this place.

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This is common sense answer

"@" symbol will suppress PHP-generated error messages. suppress, notice will occure and error handling function will be called.

isset is part of the language construct, therefore it is much faster.

Use Ternary Operators isset($dat['index']) ? $data['index'] : null, because it looks clean and does not trigger error handling

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Coming from java, I would suggest you to use the third option. This way you don't hide a code that doesn't work but you instead provide a default value when there is none.

The first way just hide an error, and the second is just way too long.

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Error suppressing with @ is know to be really slow. I've read that turning error reporting, doing something and then turning the old reporting level is still faster than just using @.

Regarding other two options - they are equal for me, but just for output, I would use 3rd variant with isset - simply looks nicer and no need to define extra function... If you are using a lot of output - then maybe function would reduce code repeat and would be more useful...

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Php has this array_key_exists function that I think is the most correct way to handle what you're doing. As for speed, here is a test program I just made:

//testing @
$t = microtime(TRUE);

$a = array('one' => 1, 'three' => 3);

for ($i = 0; $i < 1000000; $i++)
  $b = @$a['two'];

echo (microtime(TRUE) - $t)."\n";


//testing array_key_exists
$t = microtime(TRUE);

$a = array('one' => 1, 'three' => 3);

for ($i = 0; $i < 1000000; $i++)
  $b = array_key_exists('two', $a) ? $a['two'] : '';

echo (microtime(TRUE) - $t)."\n";


//testing isset
$t = microtime(TRUE);

$a = array('one' => 1, 'three' => 3);

for ($i = 0; $i < 1000000; $i++)
  $b = isset($a['two']) ? $a['two'] : '';

echo (microtime(TRUE) - $t)."\n";

and the results are:

5.9005348682404
9.6285729408264
0.32760310173035

So yeah, isset is noticeably faster.

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Time has passed, reflections on the solution

• Q. Which should I use by default?
• A. Ternary operator.

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• Q. Which is fastest?
• A. Ternary operator.

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• Q. Which is the most convenient?
• A. Custom function.

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@ error surpressing actually works like this

1. it switches off error reporting completely for the entire php thread
2. it does the operation
3. it switches error reporting back on

which is why it is not recommended

sometimes I use this:

function issetor(&$variable, $or = NULL) {
  return $variable === NULL ? $or : $variable;
}

because it is shorter to write:

echo issetor($data['two'],'');

than:

echo isset($data['two'])?$data['two']:'';

Warning: issetor($arr[$k],null); will set the $arr[$k] = null; if $arr[$k] is not already set

Other times I use custom array handling functions, depending on the situation.