LAUNCHXL-F28379D: How Interact GPIOs in For Loop ?

I'm new in the Microcontrollers programming and I'm trying to interact in a for loop with the some inputs GPIOs but i don't know how should do it.

# define Rows 4

int input_pin[Rows] = {GpioDataRegs.GPADAT.bit.GPIO1, GpioDataRegs.GPADAT.bit.GPIO2, GpioDataRegs.GPADAT.bit.GPIO3, GpioDataRegs.GPADAT.bit.GPIO4};

int r;

 for ( r = 0; r < Rows; r++)
    {
        if (&input_pins[r] == 0)
            
            do some stuff;
    }

I'm trying a code with a definition like this (this is not all the project, BTW)  but give me the error " identifier input_pins is undefined and must have a constant value) i think that input_pin it should be a volatile structure but I'm not sure how its implemented,  I'm just trying to interreact in a for loop or any kind of loop like this, any suggestions please, thanks for your time