Question

So I’ve been thinking (while reading this Java pdf)…

I know this may seem silly but why can’t I do this in c++.

float &f = new float;

Isn’t this saying the reference of f is the address of new float?

In Java, I see something like this

String s = new String("something")

String s is called a string reference.

Does the word ‘reference’ in Java have the same meaning as in C++?

Answer 1

Java references are much closer to C++ pointers rather than C++ references. In Java, you can do the following with a reference:

• Change which object it refers to
• Check whether two references are equal or unequal
• Send messages to the referenced object.

In C++, pointers have these same properties. As a result, the code you’re looking for in C++ is something like

float* f = new float;

Which is perfectly legal. For a better comparison, this Java code:

String myString = new String("This is a string!"); // Normally I wouldn't allocate a string here, but just for the parallel structure we will.
System.out.println(myString.length());

/* Reassign myString to point to a different string object. */
myString = new String("Here's another string!");
System.out.println(myString.length());

would map to this C++ code:

std::string* myString = new std::string("This is a string");
std::cout << myString->length() << std::endl;

delete myString; // No GC in C++!

/* Reassign myString to point to a different string object. */
myString = new std::string("Here's another string!");
std::cout << myString->length() << std::endl;

delete myString; // No GC in C++!

Hope this helps!