empty(3) [php man page]

EMPTY(3)								 1								  EMPTY(3)

empty - Determine whether a variable is empty

SYNOPSIS

       bool empty (mixed  $var)

DESCRIPTION

	Determine  whether a variable is considered to be empty. A variable is considered empty if it does not exist or if its value equals FALSE.
       empty(3) does not generate a warning if the variable does not exist.

PARAMETERS

	      o $var
		- Variable to be checked

	      Note

		      Prior to PHP 5.5, empty(3) only supports variables; anything else will result in a parse error. In other words, the  follow-
		     ing will not work: empty(trim($name)). Instead, use trim($name) == false.

	       No  warning  is generated if the variable does not exist. That means empty(3) is essentially the concise equivalent to !isset($var)
	      || $var == false.

RETURN VALUES

	Returns FALSE if $var exists and has a non-empty, non-zero value. Otherwise returns TRUE.

	The following things are considered to be empty:

	      o "" (an empty string)

	      o 0 (0 as an integer)

	      o 0.0 (0 as a float)

	      o "0" (0 as a string)

	      o NULL

	      o FALSE

	      o array() (an empty array)

	      o $var; (a variable declared, but without a value)

CHANGELOG

       +--------+---------------------------------------------------+
       |Version |						    |
       |	|						    |
       |	|		     Description		    |
       |	|						    |
       +--------+---------------------------------------------------+
       | 5.5.0	|						    |
       |	|						    |
       |	| empty(3) now supports  expressions,  rather  than |
       |	| only variables.				    |
       |	|						    |
       | 5.4.0	|						    |
       |	|						    |
       |	|  Checking  non-numeric offsets of strings returns |
       |	| TRUE. 					    |
       |	|						    |
       +--------+---------------------------------------------------+
EXAMPLES

       Example #1

	       A simple empty(3) / isset(3) comparison.

	      <?php
	      $var = 0;

	      // Evaluates to true because $var is empty
	      if (empty($var)) {
		  echo '$var is either 0, empty, or not set at all';
	      }

	      // Evaluates as true because $var is set
	      if (isset($var)) {
		  echo '$var is set even though it is empty';
	      }
	      ?>

       Example #2

	      empty(3) on String Offsets

	       PHP 5.4 changes how empty(3) behaves when passed string offsets.

	      <?php
	      $expected_array_got_string = 'somestring';
	      var_dump(empty($expected_array_got_string['some_key']));
	      var_dump(empty($expected_array_got_string[0]));
	      var_dump(empty($expected_array_got_string['0']));
	      var_dump(empty($expected_array_got_string[0.5]));
	      var_dump(empty($expected_array_got_string['0.5']));
	      var_dump(empty($expected_array_got_string['0 Mostel']));
	      ?>

	      Output of the above example in PHP 5.3:

	      bool(false)
	      bool(false)
	      bool(false)
	      bool(false)
	      bool(false)
	      bool(false)

	      Output of the above example in PHP 5.4:

	      bool(true)
	      bool(false)
	      bool(false)
	      bool(false)
	      bool(true)
	      bool(true)

NOTES

       Note

	      Because this is a language construct and not a function, it cannot be called using variable functions.

       Note

	       When using empty(3) on inaccessible object properties, the __isset() overloading method will be called, if declared.

SEE ALSO

       isset(3), __isset(), unset(3), array_key_exists(3), count(3), strlen(3), The type comparison tables.

PHP Documentation Group 														  EMPTY(3)

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ODBC_NEXT_RESULT(3)							 1						       ODBC_NEXT_RESULT(3)

odbc_next_result - Checks if multiple results are available

SYNOPSIS

       bool odbc_next_result (resource	$result_id)

DESCRIPTION

	Checks	if  there  are	more  result  sets  available  as  well  as  allowing  access  to  the	next  result  set via odbc_fetch_array(3),
       odbc_fetch_row(3), odbc_result(3), etc.

PARAMETERS

	      o $result_id
		- The result identifier.

RETURN VALUES

	Returns TRUE if there are more result sets, FALSE otherwise.

EXAMPLES

       Example #1

	      odbc_next_result(3)

	      <?php
	      $r_Connection = odbc_connect($dsn, $username, $password);

	      $s_SQL = <<<END_SQL
	      SELECT 'A'
	      SELECT 'B'
	      SELECT 'C'
	      END_SQL;

	      $r_Results = odbc_exec($r_Connection, $s_SQL);

	      $a_Row1 = odbc_fetch_array($r_Results);
	      $a_Row2 = odbc_fetch_array($r_Results);
	      echo "Dump first result set";
	      var_dump($a_Row1, $a_Row2);

	      echo "Get second results set ";
	      var_dump(odbc_next_result($r_Results));

	      $a_Row1 = odbc_fetch_array($r_Results);
	      $a_Row2 = odbc_fetch_array($r_Results);
	      echo "Dump second result set ";
	      var_dump($a_Row1, $a_Row2);

	      echo "Get third results set ";
	      var_dump(odbc_next_result($r_Results));

	      $a_Row1 = odbc_fetch_array($r_Results);
	      $a_Row2 = odbc_fetch_array($r_Results);
	      echo "Dump third result set ";
	      var_dump($a_Row1, $a_Row2);

	      echo "Try for a fourth result set ";
	      var_dump(odbc_next_result($r_Results));
	      ?>

	      The above example will output:

	      Dump first result set array(1) {
		["A"]=>
		string(1) "A"
	      }
	      bool(false)
	      Get second results set bool(true)
	      Dump second result set array(1) {
		["B"]=>
		string(1) "B"
	      }
	      bool(false)
	      Get third results set bool(true)
	      Dump third result set array(1) {
		["C"]=>
		string(1) "C"
	      }
	      bool(false)
	      Try for a fourth result set bool(false)

PHP Documentation Group 												       ODBC_NEXT_RESULT(3)

Linux and UNIX Man Pages

empty(3) [php man page]

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