string *ptr = new string(“Hello”); The new operator mainly does two things: It allocates enough memory to hold an object of the type requested. (In the above example, it allocates enough memory to hold this string object) It calls a constructor to initialize an object in the memory that was allocated. Now this “new” is … Read more
T *t = new T; // ^^^^^ This is a declaration of t of type T*. It is being initialized by the expression after the =. The entire new T part is the new-expression in this initializer. The new-expression causes memory to be allocated for an object of type T and then that object is … Read more
String is a class like other classes in any Object oriented programming language and we can create object of it using new keyword like we would do for creating object of any type. In your specific scenario above you have a char array and String class have a constructor overload which take char[] as input … Read more
new is for dynamic allocation (of an array on the heap in this case), and returns a pointer to the new array. [] in the declaration are for declaring it to be a stack array (and the brackets belong the right side of the variable name). So the two legal approaches your code is mixing … Read more
You just need to delete the array referenced by del: delete[] del; You are already deleting the arrays referenced by hello and bye: delete[] * del; delete[] * (del + 1); Though this would be more idiomatic: delete[] del[0]; delete[] del[1]; Or even better, avoid using new and delete altogether, taking advantage of modern C++ … Read more
C++ and Java have similar syntax but not always means the same. In Java all objects are references, so when you’re doing Classname obj; you’re creating a empty reference to an object, so you need to assign something to it. Classname obj; //here obj is pointing to nothing. obj = new Classname(); //here obj is … Read more
From “New and delete (C++)” on Wikipedia: If not enough memory is available in the free store for an object of type T, the new request indicates failure by throwing an exception of type std::bad_alloc. This removes the need to explicitly check the result of an allocation. 2 solved what happens if I call new … Read more
You would utilize the alloc and init (or more specialized initializer) provided by NSObject. For example, something like the following should work: int fromuser, a; NSMutableArray objectArray = [[NSMutableArray alloc] initWithCapacity:fromuser]; for (a = 0; a < fromuser; a++) { MyObject *obj = [[MyObject alloc] init]; [objectArray addObject:obj]; [obj release]; //If not using ARC } … Read more
The compiler will translate a call to a member function into a call to a static function, with an implied this parameter pointing to the object. That means the contents of the object, valid or invalid, are not relevant to the whether the call is made. This changes if the method is virtual, since the … Read more