This question is merely out of interest and trying to understand something about memory management in object-oriented languages. It is not specific to one language, but I just want to understand as a general principle.
What I want to know is how the definition of an object reference is stored compared to the instance of that reference.
When you define and object in OO source code, e.g. in Java, without instantiating it:
String s;
How does this get stored? How does the memory usage of this definition differ from when the object is actually instantiated:
s = new String("abc");
? Is there a general principle that applies to all OO languages in terms of how memory is allocated or do different language implementers use different techniques for allocating memory?
Normaly when we declare a refrence like String s; it is created as a normal variable just like int , float but this type of variable hold the memory address ( it similar concept as pointers in C language) but when we use s = new String(“abc”);, it creates an object in heap and assign that address to the reference variable s.