Declaration: TParticles.NParticlesOfClass[ClsIx: integer]: integer;
The readonly property NParticlesOfClass returns the number of particles belonging to the class ClsIx. The parameter ClsIx may assume values between 0 and NClasses. Specifying an invalid class number results in a zero return value.

Hint: In order to access the particles currently loaded in the particle editor you can use the pre-declared global variable PEData.