arrays - Receiving a null error "Unhandled Exception: System.NullException: Value cannot be null" C# -

hello new in programming world , im having little problem simple program. created array , passed through constructor class named "temperature." im trying find max number of array , return method seems has no value, therefore causing error.

namespace tempapp {     class program     {         static void main(string[] args)         {             temperature atemperatureobject = new temperature();             double[] temp = new double [7];             string invalue;              (int = 0; < temp.length; i++)             {                 console.write("enter temperature day {0}: ", + 1);                 invalue = console.readline();                 temp[i] = double.parse(invalue);             }              double highesttemp = atemperatureobject.gethighesttemp();             double lowesttemp = atemperatureobject.getlowesttemp();             double averagetemp = atemperatureobject.getaveragetemp();              displayresults(highesttemp, lowesttemp, averagetemp);         }          static void displayresults(double high, double low, double avg)         {             console.write("highest temp: " + high);             console.write("lowest temp: " + low);             console.write("average temp: " + avg);         }     } }    namespace tempapp {     class temperature     {         private double[] temp;          public temperature()         {          }          public temperature(double[] temperature)         {             temp = temperature;         }          public double gethighesttemp()         {             double highesttemp = temp.max();             return highesttemp;         }          public double getlowesttemp()         {             double lowesttemp = temp.min();             return lowesttemp;         }          public double getaveragetemp()         {             double averagetemp = temp.average();             return averagetemp;         }     } } 

your temperature object has 2 constructors, first default parameterless constructor, , second 1 one takes parameter , sets temp field.

you're using parameterless constructor:

temperature atemperatureobject = new temperature(); double[] temp = new double [7]; 

there no place in code pass above array atemperatureobject object.

that's why you're getting null reference exception.

change code use other constructor , should solve problem. note in order so, have declare array before can instantiate temperature class:

double[] temp = new double [7]; temperature atemperatureobject = new temperature(temp);