The syntax MyClass *myArray = new MyClass[size](); allows you to value-initialize the elements when they are trivial simple types (like integers, etc, thus setting them to 0), but it is not very meaningful for elements of class/struct types, so the () is usually omitted for those types. new[] can only call default constructors on class/struct types, it does not allow you to call non-default constructors.
However, a way to handle that is to use placement-new instead, which would then allow you to construct each MyClass object individually, even with different parameter values if needed.
// allocate raw memory to hold the objects array...
char *myArrayBuf = new char[sizeof(MyClass) * NumberOfItems];
/* alternatively, in C++11 and later:
#include <type_traits>
using element_type = std::aligned_storage<sizeof(MyClass), alignof(MyClass)>::type;
element_type *myArrayBuf = new element_type[NumberOfItems];
*/
// call the constructor on each object in the array...
MyClass *myArray = reinterpret_cast<MyClass*>(myArrayBuf);
for(int i = 0; i < NumberOfItems; ++i) {
new(&myArray[i]) MyClass(givenParameter);
}
// use myArray as needed ...
// call the destructor on each object in the array...
for(int i = 0; i < NumberOfItems; ++i) {
myArray[i].~MyClass();
}
// deallocate the raw memory for the array...
delete[] myArrayBuf;
In C++11 and later, this would be easier to handle using a std::vector instead (which you should be using anyway):
#include <vector>
std::vector<MyClass> myArray;
myArray.reserve(NumberOfItems);
for(int i = 0; i < NumberOfItems; ++i) {
myArray.emplace_back(givenParameter);
}
// use myArray as needed ...
Prior to C++11, you can still use std::vector, but it would require copy-constructing the array elements:
#include <vector>
std::vector<MyClass> myArray;
myArray.reserve(NumberOfItems);
for(int i = 0; i < NumberOfItems; ++i) {
myArray.push_back(MyClass(givenParameter));
}
// use myArray as needed ...
