PHP supports the following types:
The type of a variable is usually not set by the programmer;
rather, it is decided at runtime by PHP depending on the context in
which that variable is used.
If you would like to force a variable to be converted to a certain
type, you may either cast the variable or
use the settype() function on it.
Note that a variable may behave in different manners in certain
situations, depending on what type it is at the time. For more
information, see the section on Type Juggling.
Integers can be specified using any of the following syntaxes:
$a = 1234; # decimal number
$a = -123; # a negative number
$a = 0123; # octal number (equivalent to 83 decimal)
$a = 0x12; # hexadecimal number (equivalent to 18 decimal)
The size of an integer is platform-dependent, although a
maximum value of about 2 billion is the usual value
(that's 32 bits signed).