The syntax is
struct Motor {
int stepPin;
int dirPin;
int direction;
int RPM;
bool run;
int steps;
} myMotors[] = {
{13,14,15,16,false,0
{23,14,15,16,false,0},
{33,14,15,16,false,0},
{43,14,15,16,false,0}
};
(I haven’t tried but I don’t think your syntax is valid C++11. The [0] = {...} syntax is a C99 designated initializer feature, not supported in C++ until C++20 which is not what our compiler is.)