CXII. Variable Functions
Introduction
For information on how variables behave, see the Variables entry in the Language Reference section of the manual.
Runtime Configuration
The behaviour of these functions is affected by settings in php.ini.
Table 1. Variables Configuration Options
NameDefaultChangeableunserialize_callback_func""PHP_INI_ALLHere's a short explanation of the configuration directives.
unserialize_callback_func
string
The unserialize callback function will called (with the undefined class' name as parameter), if the unserializer finds an undefined class which should be instanciated. A warning appears if the specified function is not defined, or if the function doesn't include/implement the missing class. So only set this entry, if you really want to implement such a callback-function.
See also unserialize().
Table of Contents
doubleval -- Alias of
floatval()
empty -- Determine whether a variable is emptyfloatval -- Get float value of a variableget_defined_vars -- Returns an array of all defined variablesget_resource_type -- Returns the resource typegettype -- Get the type of a variableimport_request_variables -- Import GET/POST/Cookie variables into the global scopeintval -- Get integer value of a variableis_array -- Finds whether a variable is an arrayis_bool -- Finds out whether a variable is a boolean is_callable -- Verify that the contents of a variable can be called as a functionis_double -- Alias of
is_float()
is_float -- Finds whether a variable is a floatis_int -- Find whether a variable is an integeris_integer -- Alias of
is_int()
is_long -- Alias of
is_int()
is_null -- Finds whether a variable is
NULL
is_numeric -- Finds whether a variable is a number or a numeric stringis_object -- Finds whether a variable is an objectis_real -- Alias of
is_float()
is_resource -- Finds whether a variable is a resourceis_scalar -- Finds whether a variable is a scalaris_string -- Finds whether a variable is a stringisset -- Determine whether a variable is setprint_r -- Prints human-readable information about a variableserialize -- Generates a storable representation of a valuesettype -- Set the type of a variablestrval -- Get string value of a variableunserialize -- Creates a PHP value from a stored representationunset -- Unset a given variablevar_dump -- Dumps information about a variablevar_export -- Outputs or returns a parsable string representation of a variable
