How to initialize array of structure in C?

Question

The scenario is that I have nested structure definition, and I have an array of 10 such structure. What I want is to initialize each of the element of both parent and the child structure with zero. Code is given below:

struct PressureValues
{

   float SetPressure;
   float ReadPressure;

};

struct CalibrationPoints
{

   float SetTemperature;
   struct PressureValues PressurePoints[10];

};

extern volatile struct  CalibrationPoints code IntakeCalibrationPoints[10];

extern volatile struct  CalibrationPoints code DischargeCalibrationPoints[10];

I know the lengthy method of initializing each structure element with zero using loop, but I am looking for a short method of initializing all elements to zero. Or what is the default initialize value of array of structure (containing floats only), is it zero or any random value?

Answer 1

volatile struct CalibrationPoints IntakeCalibrationPoints[10] = { { 0 } };
volatile struct CalibrationPoints DischargeCalibrationPoints[10] = { { 0 } };

This will initialise all elements to zero.

The reason that this works is that when you explicitly initialise at least one element of a data structure then all remaining elements which do not have initialisers specified will be initialised to zero by default.