动态数组分配随机崩溃

Question

I've been trying to learn about pointers and allocating space during runtime. I decided to change one of my older assignments, a weather temperature array into a dynamically allocated array. I think I am close to being done but everytime I run it and enter a temperature my program crashes with no warning. I want to understand why it is crashing.

int dayNumber;
double fahrenheit = 0;
double cTemperature = 0;
const double MAXIMUM_TEMPERATURE = 60;// constants for mix/max
const double MINIMUM_TEMPERATURE = -90 ;
const int MAXIMUM_DAYS = 365;
const int MINIMUM_DAYS = 1;
double *ptrTemperatures;

cout << "How many days would you like to enter? ";
dayNumber = myValidation::GetValidInteger(MINIMUM_DAYS, MAXIMUM_DAYS);
try
{
    double *ptrTemperatures = new double[dayNumber];
}
catch(exception e)
{
    cout << "Failed to allocate memory: " << e.what() << endl;
}
cout << "\n\nTEMPERATURE REPORTER\n____________________________\n Please Enter the temperature for each day.";

for(int dayCount = 0; dayCount < dayNumber; dayCount++){
    cout << "Celsius Temperature for Day " << (dayCount + 1) << ": ";
    ptrTemperatures[dayCount] = myValidation::GetValidDouble(MINIMUM_TEMPERATURE, MAXIMUM_TEMPERATURE);
}





delete[] ptrTemperatures;
return 0;

Answer 1

You should change your allocation as follows:

try
{
   ptrTemperatures = new double[dayNumber];
}

Answer 2

You're declaring a new variable called ptrTemperatures inside your try clause. This is the one you're allocating. The variable outside the try remains unallocated and uninitialized, so you are accessing random memory.