Since Pd is used on several platforms, many ordinary types of variables, like int, are re-defined. To write portable code, it is reasonable to use types provided by Pd.
Apart from this there are many predefined types, that should make the life of the programmer simpler.
Generally, Pd-types start with t_.
|t_float||floating point value|
|t_gpointer||pointer (to graphical objects)|
|t_signal||structure of a signal|
|t_sample||audio signal-value (floating point)|
|t_outlet||outlet of an object|
|t_inlet||inlet of an object|
|t_newmethod||pointer to a constructor (new-routine)|