Thread: Why does this code not function....

Code:

#include <iostream.h>

class MyClass {
public:
    int *array;	
    int *tmparray;
	
	MyClass(int s) { 
		size = s;
		array = new int[size];
	}

	~MyClass() {
		delete [] array; 
	}

	int get_length() {
		return size;
	}
	
	void resize(int s) { 
		delete [] array;
		size = s;
		array = new int[size];
	}
	
	void clear_all() {
		for (c = 0; c < size; ++c)
			array[c] = NULL;
	}
	
	int get_average() { 
		for (c = 0; c < size; ++c)
			average+=array[c];
		if (size != 0)
			return (average/size);
		else
			return (-1);
	}
	
	int find_low() { 
		lowspot = 0;
		for (c = 0; c < size; ++c) {
			if (array[c] < array[lowspot])
				lowspot = c;
		}
		return (lowspot);
	}
	
	void output_all() { 
		for (c = 0; c < size; ++c) 
			cout << array[c] << endl;
	}
	
	void sel_sort() { 
		tmparray = new int [size];
		tmpl = 0;
		for (c = 0; c < size; ++c) {
			 tmpl = find_low();
			 tmparray[c] = array[c];
			 array[c] = 99999;
		}
		array = tmparray;
		delete [] tmparray;
	}

private:
	int size;
	int c;
	int average;
	int lowspot;
	int tmpl;
};

int main()
{
	
	int averg =0;
	MyClass Array(3);
	Array.array[1] = 6;
	Array.array[2] = 3;
	Array.array[3] = 9;
	Array.output_all;
	Array.sel_sort;
	Array.output_all;

	return(0);
}

I'm not very good at OOP yet, so I was wondering what I can do to this code to get rid of the error (probably from memory management) and to make the methods output_all and sel_sort work properly... =|

If anyone could help, I'd appreciate it

You should keep variables at the lowest scope possible. One of your problems is that you're using the same variable for all the loops, so one loop is messing up another. Also the selection sort should probably be done in place -

Code:

#include <iostream>

using namespace std;


class MyClass {
public:
    int *array;	
    	
	MyClass(int s) { 
		size = s;
		array = new int[size];
	}

	~MyClass() {
		delete [] array; 
	}

	int get_length() {
		return size;
	}
	
	void resize(int s) { 
		delete [] array;
		size = s;
		array = new int[size];
	}
	
	void clear_all() {
		for (int c = 0; c < size; ++c)
			array[c] = NULL;
	}
	
	int get_average() { 
		for (int c = 0; c < size; ++c)
			average+=array[c];
		if (size != 0)
			return (average/size);
		else
			return (-1);
	}
	
	int find_low(int start=0) { 
		int lowspot = start;
		for (int c = start; c < size; ++c) {
			if (array[c] < array[lowspot])
				lowspot = c;
		}
		return lowspot;
	}
	
	void output_all() { 
		for (int c = 0; c < size; ++c) 
			cout << array[c] << endl;
	}
	
	void sel_sort() { 
		
		for ( int c = 0; c < size; ++c) {
			 int low = find_low(c);
			 int temp = array[c];
			 array[c]=array[low];
			 array[low]=temp;
		}
		
	}

private:
	int size;
	int average;
};

int main()
{
	
	int averg =0;
	MyClass Array(5);
	Array.array[0] = 6;
	Array.array[1] = 3;
	Array.array[2] = 9;
	Array.array[3] = 22;
	Array.array[4] = 1;
	Array.output_all();
	Array.sel_sort();
	Array.output_all();

	return 0;
}