C++ I have a creature base class, and 2 derived class from it- ant and doodlebug
ID: 3907482 • Letter: C
Question
C++
I have a creature base class, and 2 derived class from it- ant and doodlebug
I also have a gameboard class which has a 2d array where each element is either one of the 2 creatures or Null
If inside a function I want to move a creature across the gameboard, how would I go about doing so? and How would I check which creature is in which spot?
(I already made the function in each of the creature classes int ant::getType() { return 1) and doodlebug::getType{return 2) with the virtual function virtual int creature::getType() = 0; ) I also made copy constructor, assignment constructor and destrucor in creature class.
Example- I want to move an ant right.
Right now this is what I have and It is not working, what is the correct way to do this?
Code:
board::moveAntRight() {
if(this->grid[x][y] != NULL) {
if(this->grid[x][y]->getType() == 1) {
ant* thisAnt = (ant*)grid[x][y];
if(this->grid[x+1][y]==NULL) {
//ant moves right
grid[x+1][y] = thisAnt;
ant* newAnt = thisAnt;
delete thisAnt;
newAnt->turnsMoved++;
}
}
}
What am I doing wrong and what is the correct way to do this? Thanks
Explanation / Answer
board::moveAntRight() {
if(this->grid[x][y] != NULL) {
if(this->grid[x][y]->getType() == 1) {
ant* thisAnt = (ant*)(this->grid[x][y]);
if(this->grid[x+1][y] == NULL) {
//ant moves right
this->grid[x+1][y] = thisAnt;
// ant* newAnt = thisAnt;
// delete thisAnt;
// newAnt->turnsMoved++;
this->grid[x][y] = NULL;
thisAnt->turnsMoved++;
}
}
}
}
There was a missing bracket but I'm assuming that it was a copying mistake.
The mistake you were doing were using delete on thisAnt.
Since that is a pointer to the object and doesn't contain the object itself, you were deleting thisAnt itself.
Instead set grid[x][y] to point to NULL and make sure that the element next to it points to the same object.
There is no need to make a new pointer, pointing to the same obect as if you call delete on one, the other one would point to NULL.
I hope this made sense.
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