The following functions operate on PHP variables. There are functions for getting and setting the type of a variable, as well as various ways to encode and decode variables for storage.
bool define(string var_name, mixed value[, intcase_sensitive])Define a constant value
int defined(string constant_name)Test if a constant is defined
double doubleval(mixed var)Get the double-precision value of a variable
string getenv(string varname)Get the value of an environment variable
string gettype(mixed var)Return the type of the variable
int intval(mixed var [, int base])Get the integer value of a variable using the optional base for the conversion
bool is_array(mixed var)Return
trueif variable is an arraybool is_double(mixed var)Return
trueif variable is a doublebool is_float(mixed var)An alias for
is_double( )bool is_int(mixed var)An alias for
is_long( )bool is_integer(mixed var)An alias for
is_long( )bool is_long(mixed var)Return
trueif variable is a long (integer)bool is_object(mixed var)Return
trueif variable is an objectbool is_real(mixed var)An alias for
is_double( )bool is_string(mixed var)Return
trueif variable is a stringstring pack(string format, mixed arg1, mixedarg2, ...)Take one or more arguments and pack them into a binary string according to the format argument
bool is_real(mixed var)An alias for
is_double( )bool is_string(mixed var)Return
trueif variable is a stringvoid putenv(string setting)Set the value of an environment variable
string serialize(mixed variable)Return a string representation of variable (which can later be unserialized)
int settype(string var, string type)Set the type of the variable
string strval(mixed var)Get the string value of a variable
array unpack(string format, string input)Unpack binary string into named array elements according to format argument
mixed unserialize(string variable_representation)Take a string representation of variable and recreate it
void var_dump(mixed var)Dump a string representation of variable to output