{"id":8702,"date":"2020-04-27T11:00:59","date_gmt":"2020-04-27T02:00:59","guid":{"rendered":"https:\/\/www.gigas-jp.com\/appnews\/?p=8702"},"modified":"2020-04-24T19:16:44","modified_gmt":"2020-04-24T10:16:44","slug":"isset-vs-empty-in-php","status":"publish","type":"post","link":"https:\/\/www.gigas-jp.com\/appnews\/archives\/8702","title":{"rendered":"Isset VS Empty In PHP"},"content":{"rendered":"\n

Today I will walk through the difference between isset & empty , build in functions in PHP. <\/p>\n\n\n\n

Iseet<\/h3>\n\n\n\n

It checks the variable to see if it has been set, in other words, it checks to see if the variable is any value except NULL or not assigned a value. ISSET returns TRUE if the variable exists and has a value other than NULL. That means variables assigned a ” “, 0, “0”, or FALSE are set, and therefore are TRUE for ISSET.<\/p>\n\n\n\n

Empty<\/h3>\n\n\n\n

It checks to see if a variable is empty. Empty is interpreted as: ” ” (an empty string), 0 (0 as an integer), 0.0 (0 as a float), “0” (0 as a string), NULL, FALSE, array() (an empty array), and “$var;” (a variable declared, but without a value in a class.)<\/p>\n\n\n\n

Lets do some comparisons.<\/p>\n\n\n\n

Non declared variable<\/h4>\n\n\n\n
isset($novar) \u2013 Return FALSE\nempty($novar) \u2013 Return TRUE<\/code><\/pre>\n\n\n\n
Null Variable
<\/h4>\n\n\n\n
$null = NULL; \nisset ($null) - Return FALSE \nempty ($null) - Return TRUE<\/code><\/pre>\n\n\n\n
Empty String
<\/h4>\n\n\n\n
$emptyString = \"\"; \nisset($emptyString) - Return TRUE \nempty($emptyString) - Return TRUE <\/code><\/pre>\n\n\n\n
This will be the same result for zero case.<\/font><\/font><\/em><\/p>\n\n\n\n
Boolean value<\/h4>\n\n\n\n
$tbl = TRUE; \n$fbl = FALSE; <\/code><\/pre>\n\n\n\n
Isset<\/font><\/font><\/strong> . Will Return TRUE For Both Cases <\/font><\/font><\/em>
Empty<\/font><\/font><\/strong>
<\/p>\n\n\n\n
empty($tbl) - Return FALSE \nempty($fbl) - Return TRUE<\/code><\/pre>\n\n\n\n
Empty Array<\/h4>\n\n\n\n
$arr = [];
The result will be true for both isset<\/strong> and empty<\/strong><\/p>\n\n\n\n
Empty object <\/h4>\n\n\n\n
$obj = new stdClass (); \nisset ($obj) \u2013 return TRUE \nempty ($obj) \u2013 return FALSE<\/code><\/pre>\n\n\n\n
Note: <\/em><\/strong>Isset only accepts single variable within its parenthesis. Passing others will proceed to error. For example
isset(strtoupper($var)) – this will proceed to error.<\/p>\n\n\n\n
By Yuuma<\/p>\n
\n            
<\/g:plusone><\/div>\n            
 \"\u3053\u306e\u30a8\u30f3\u30c8\u30ea\u30fc\u3092\u306f\u3066\u306a\u30d6\u30c3\u30af\u30de\u30fc\u30af\u306b\u8ffd\u52a0\"<\/a>