Thread: Class Variables

ClassName::MemberName from within the member function

If the function and members are of the same class then you don't have to do anything special, just use the members in the function like you would anywhere else, unless the members and function arguments have the same names. If that's the case then you could have problems, so be explicit.

Code:

#include <iostream>
#include <string>

using namespace std;

class test {
  int a, b;
public:
  void function(int a, int b)
  {
    this->a = a;
    this->b = b;
  }

  void print()
  {
    cout<< a <<endl<< b <<endl;
  }
};

int main()
{
  test t;

  t.function(1, 2);
  t.print();
}

yeah, use the 'this->' variable

No, I don't think so - it's a matter of SCOPE it will probably just use the local variables.

Originally posted by Travis Dane
hmm, so 'this->' is a way to assure that it uses the local function
variables, and how can i assure it uses the class variables?

No, you're confused.

the keyword 'this' represents a pointer to the object you are currently in, so

this->membername

says "the member of the current object called membername"

In other words, that refers to the MEMBER not the variable local to the function. To use the one local to the function you just use the variable name -- the most local variable with the same name is the one that's used.

The other way you can access the object's member (IE the one not passed to the function), is how I mentioned with the scope resolution operator

ClassName::MemberName

which will have the same end result as

this->MemberName

Code:

class test
{
public:
void outputsomething(int a);
private:
int a;
};

void test::outputsomething(int a)
{
cout << a; // output the passed var
cout << this->a; // output the class's var
}