A two-stroke, or two-cycle, engine is a type of internal combustion engine which completes a power cycle with two strokes (up and down movements) of the piston during only one crankshaft revolution. This is in contrast to a  four-stroke engine , which requires four strokes of the piston to complete a power cycle. two-stroke engine, in this case with an expansion chamber illustrates the effect of a reflected pressure wave on the fuel charge. This is essential for maximum charge pressure (volumetric efficiency) and fuel efficiency. It is used on most high-performance engine designs.
More than that, because the array is a reference type, the amount of memory that resides on the stack along with the containing struct for a particular array is always equivalent to the native int pointer size (which is 32 on 32 bit Windows and 64 on 64 bit windows).
struct Person is a datatype and can be used in exactly the same way as we use int, float, or other C++ datatypes. struct Person is not a variable name and to use a struct you must first define variables of that type. This can be done in two ways. When you originally define a struct you can define a variable or variables. In the definition above, tom is the name of a variable of type struct Person. We could declare more than one variable this way.