In
Java, all objects are dynamically allocated on Heap.
are often "> this is often different from
C++ where objects can be allocated memory either on Stack or on Heap. In
C++,
once we allocate
the thing using new(),
the thing is allocated on Heap, otherwise on Stack if not global or static.
In
Java,
once we only declare a variable of
a category type, only a reference
is made (memory
isn't allocated for the object). To allocate memory to an object, we must use new().
therefore the object
is usually allocated memory on the heap (See this for more details).
For example, the following program fails
within the compilation. The compiler gives the error “Error here because t
isn't initialized”.
class Test {
// class contents
void show()
{
System.out.println("Test::show() called");
}
}
public class Main {
// Driver Code
public static void main(String[] args)
{
Test t;
// Error here because t
// is not initialzed
t.show();
}
}
Allocating memory using new() makes the above program work.
class Test {
// class contents
void show()
{
System.out.println("Test::show() called");
}
}
public class Main {
// Driver Code
public static void main(String[] args)
{
// all objects are dynamically
// allocated
Test t = new Test();
t.show(); // No error
}
}