Object Instantiation in C : `new` Keyword vs. Direct Initialization?

Understanding Instantiation of Objects: With or Without 'new'

When creating objects in programming, two approaches emerge: using the 'new' keyword or instantiating without it. Beyond dynamic memory allocation, a crucial question arises: is there a functional distinction between these two methods?

Let's examine the following code snippets:

Time t (12, 0, 0); // t is a Time object
Time* t = new Time(12, 0, 0); // t is a pointer to a dynamically allocated Time object

In the first line, the 't' variable is created locally, typically on the stack. It holds an instance of the 'Time' object that is destroyed once its scope ends.

Contrastingly, the second line utilizes the 'new' operator to allocate memory dynamically and initializes the 'Time' object within that block. Consequently, the variable 't' stores the address of the dynamically allocated memory instead of the object itself. This dynamic allocation occurs on the heap by default and necessitates the use of 'delete' to release the allocated memory later.

Thus, the functional difference lies in the scope and lifetime of the created object. In the first case, the object is local and destroyed at the end of its scope, while in the second case, the object remains in existence until explicitly deleted.

It's important to note that the localization of variables on the stack and dynamic objects on the heap is a common implementation practice. However, the C standard defines these objects solely based on their lifetime, not their physical location in memory.

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