Why you need to master the LLDB
1. NSlog can resolve simple problem
2. LLDB can solve tricky problem
3. LLDB can save you many hours
class Stack{
    public:
        int maxLen;
        int count;
        char* array;
    public:
        Stack(int max){
            count = 0;
            maxLen = max;
            array = new char[maxLen];
        }
        void push(char ch){
            if(count < maxLen){
                array[count] = ch;
                count++;
            }
        }
        char pop(){
            char ch;
            if(count > 0){
                ch = array[count-1];
                count--;
            }
            return ch;
        }
        bool isEmpty(){
            return count == 0;
        }
        int size(){
            return count;
        }
        ~Stack(){
            if(array)
                delete[] array;
        }
};