Thread: Stack topElem function question

I have a function to get the top element from a stack...but I'm having a problem calling it

Code:

void stack::topElem(el_t& elem)
{
	if(isEmpty())
	{
		stackError("stack is empty");
	}
	else
	{
		elem = el[top];
	}
	
}

problem is I didn't write this the professor did...I would've just returned something but I have no idea what to put in the parameters. I though possibly this:

i

Code:

f ((let != '*') && (let != '+') && (let != '-') && (let != '/'))
      { 
		  thisStack.push(int(mystring[i]));
      }
	  else
	  {
		  thisStack.pop(thisStack[thisStack.topElem(?????)]);
	  }

Those ??? symbolize my confusion. Any help would be appreciated....

As you can see by the "&" in the parameter declaration, the function can change the parameter passed in. So whatever you want the function to change, you pass in.