How Do I Create a Variable Without Initializing It?

[tylara67]

I just switched universities and am taking a data structures class now. I have the prerequisite intro to OOD class from my previous university, but they only taught Java, and this class has us do all projects in both Java and C++.

I'm trying to make a fairly simple linked list class but I want its link to the next element to be empty until the constructor initializes it.

Here's a simplified version to illustrate the problem:

class foo {
   int val;
   foo bar;

public:
   foo (int[]);
   int getValue() {return value;}
   int getSum();

private:
   foo() {val=0;}
}

foo::foo(int[] arr) {
   val = arr[0];
   // if more entries in arr, assign bar to be a new foo(rest of arr)
   // otherwise make bar a new foo()
}

int foo::getSum() {
   int temp = 0;
   if(val!=0) // if val is zero, assume this the last link in the list
      temp = bar.getSum();
   return temp+val;
}

I just want to set aside a location in memory called bar for a foo object, without actually assigning it any initial content, the same way I can for the int val. If it automatically creates a new foo to go in bar, then it will of course make a foo bar' to go in bar, a foo bar'' to go in bar', and so on ad infinitum.

Should I be using pointers for this? I'm not really familiar with them since, as I said, all my past experience is with Java. Any help is appreciated!

[hamsterman]

Yes, you need pointers. see http://cplusplus.com/doc/tutorial/dynamic/
your class could be

class foo {
   int val;
   foo* next;

public:
   foo() { val = 0; next = 0; }
}

Then in foo::getSum instead of checking val, check next. Also . becomes ->

[tylara67]

That was exactly what I needed. Thanks for the help!