PHP Checking input with isset

Question

In order to check if an input field is empty or has any value, will the following both methods work in same way? Or is any of them better than other?

if ($options['url']) {
    ..
}

Or

if ( isset ($options['url']) &&  ($options['url']!="") ) {
    ..
}

if key does not exist in array, then a NOTICE will be thrown — rabudde, Jun 27 '12 at 10:52
possible duplicate of [Why check both isset() and !empty()](http://stackoverflow.com/questions/4559925/why-check-both-isset-and-empty) — Michael Berkowski, Jun 27 '12 at 10:55

score 2 · Accepted Answer · answered Jun 27 '12 at 10:53

Without checking with isset() you will get at least a notice message if $options is not an array or the index url does not exist. So isset() should be used.

You could also use

if (! empty($options['url'])) {
    ...
}

Empty() checks for any false value (like an empty string, undefined, etc...).

score 1 · Answer 2 · answered Jun 27 '12 at 10:53

1

Isset determine if a variable is not NULL and is set.

($options['url']) determine if a variable return true

answered Jun 27 '12 at 10:53

Antonio Ciccia

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score 1 · Answer 3 · answered Jun 27 '12 at 11:01

The code below only checks that the value, assuming the key exists, is true. A notice will be fired if the key doesn't exist. if ($options['url']) { .. }

isset will tell you if the key exists and the value is not null.

I'd use empty as it will return false if the key doesn't exist and it will also return false if the key does exist yet the value is empty.

score 1 · Answer 4 · answered Jun 27 '12 at 11:03

No.

The $options['url']!=""checks if variable is empty,

while isset($options['url']) checks if the variable has been set or is not NULL.

Anyway, calling `isset()` always on variables or array keys that may or may not exist must be a rule.

or you'll get all those 'undefined' warnings...

Salman A · Answer 5 · 2012-06-27T11:20:18.507

The following should be sufficient:

if (isset($options["url"]) && $options["url"]) {
   // ...
}

The isset() is used to check if a specific key is present in the array (and to avoid the undefined index notice). It is a good programming practice. You can also use the array_key_exist() function in this case but isset is usually faster.
When an expression such as $options['url'] is used inside a boolean context; its truthiness is checked (see the converting to boolean section). The empty() function produces identical result for most expressions.

PHP Checking input with isset

5 Answers5

Anyway, calling isset() always on variables or array keys that may or may not exist must be a rule.

Anyway, calling `isset()` always on variables or array keys that may or may not exist must be a rule.