Why can't we use pointers in Java? [duplicate]

Answer 1

You can access pointer mechanics using java.misc.unsafe, but that's... mmm... unsafe.

Ah, about replacing concept. What aspect are you interested in? Variables are already represented by references to them - that's one point of view. If you need pointers to implement efficient data structures, you, most probably already have one, or there is a library providing that feature, or you can write some native code and call it from java wrapper. Anyway, please define aspects you are interested in and maybe community will give you more detailed answer.

Answer 2

The most difficult thing to manipulate in any programming language is with pointers. If u just miss something you get lots of errors namely segmentation faults. Java is one such language providing users the flexibility to do things using CALL BY VALUE .

Answer 3

It's good isn't it? You don't have pointers in the C programming sense, the Virtual Machine looks after all that. However, that's not to say you don'f have have similar capabilities. For example, variables for objects are references, when you pass a variable for an object you are passing a reference which is sort of a pointer. You might also use a variable to store the index of an item in an array, that again is a kind of pointer in a programmatical sense.

Answer 4

Everything in Java is accessed only through pointers. Java references are pointers. The creator of java Dr.Gosling says this in his book, "The Java Language Specification" (somewhere around p.40 in one edition).

In fact another book "The Java Virtual Machine" says: "A reference is a pointer to a pair of pointers; one of theses two pointers points to another pointer [...]".

There are marked differences between Java references and C pointers but nevertheless references are pointers.

Answer 5

In Java any reference to a simple type is always by value and any reference to an object is always a pointer except in cases of special objects.

Answer 6

Java follows the principle of call by value. So if you create an object, you will get back a copy of a reference to the created object in the heap space. This copy of a reference is what a variable gets assigned to. If you then use this variable as an argument for a method call, again a copy of that reference is created and used instead. Java never uses references or pointers! Everything in java is a copy. Hence Java follows the call by value principle.