PHP supports the following types:
integer
double
string
array
object
pdfdoc (only if enabled PDF support)
pdfinfo (only if enabled PDF support)
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 a the time. For more information, see the section on Type Juggling.