Why does my variable keep changing to -858993460?

This is a discussion on Why does my variable keep changing to -858993460? within the C++ Programming forums, part of the General Programming Boards category; I am trying to simulate a elevator program and i have 2 classes, 1 elevator class and 1 scheduler class. ...

  1. #1
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    Why does my variable keep changing to -858993460?

    I am trying to simulate a elevator program and i have 2 classes, 1 elevator class and 1 scheduler class. Strange thing is when i run my prog, the variable for "current floor" which i stored in elevator class is always reset to -858993460 even though i reset it using a function to 0. Declaring it as static either doesn't seem to work or i do not really know how to declare it. Can someone pls help me?


    #include <iostream.h>
    #include <stdlib.h> //for the rand and srand function
    #include <time.h> //for the time function
    #include <conio.h> //for the getche in the pause

    class Elevator{
    public:
    void up(); //move up function
    void down(); //move down function
    int getfloor(); //get current floor status
    void setfloor(int floor); //sets the floor
    void open(); //checks and opens the door function
    void close(); //checks and closes the door function
    int getdoor(); //get current door status
    void setdoor(int door); //sets the foor status
    void bell(); //mux i say more?
    void reset(); //reset button to reset elevator
    int door;
    int floor;
    int pause(void); //pause function
    int cfloor; //current floor
    int cdoor; //current door status

    private:

    };


    #include "elevator.h"

    void Elevator::reset(){ //resets it to 1st floor and closes the door
    setdoor(0); //sets to close
    setfloor(0); //sets to 1st floor
    cout<<"Elevator::reset->Resetting elevator\n";
    cout<<"Elevator::reset->Current floor of elevator is "<<getfloor()<<endl;
    cout<<"Elevator::reset->Current door of elevator is "<<getdoor()<<endl;
    pause();

    }


    void Elevator::up(){ //going up
    cout<<"Elevator::up->cfloor value is "<<cfloor<<endl;
    if(cfloor==0){
    cout<<"Elevator::up->This msg only happens when cfloor is 0 or elevator is on 1st floor"<<endl;
    cout<<"Elevator::up->Current floor is 1st floor\n";
    if(cdoor==0){ //sets this condition becoz of the reset
    cout<<"Elevator::up->This msg shows up when cdoor is 0 and its gonna invoke the open()"<<endl;
    open(); //door may be close on 1st floor due to reset
    }
    close(); //closes the door
    setfloor(1); //sets floor to 2nd floor
    cout<<"Elevator::up->This shows when setfloor(1) is used"<<endl;
    cout<<"Elevator::up->Current floor is "<<getfloor()<<endl;
    cout<<"Elevator::up->Second floor reached\n";
    open(); //opens the door
    bell(); //sounds the bell and light

    }
    else {
    cout<<"Elevator::up->This msg shows up when cfloor is 1 which means elevator is on 2d floor"<<endl;
    cout<<"Elevator::up->Current floor is 2nd floor, we are at the top!\n";
    setfloor(1);
    }
    }

    void Elevator::down(){ //going down
    cout<<"Elevator::down->cfloor value is "<<cfloor<<endl;
    if(cfloor==1){
    cout<<"Elevator::down->This msg only happens when cfloor is 1 or elevator is on 2nd floor"<<endl;
    cout<<"Elevator::down->Current floor is 2nd floor\n";
    close();
    setfloor(0);
    getfloor();
    cout<<&quot;Elevator::down->First floor reached\n";
    open();
    bell();

    }
    else {
    cout<<"Elevator::down->This msg only happens when cfloor is 0 or elevator is on 1st floor"<<endl;
    cout<<"Elevator::down->Current floor is 1st floor, we are at the bottom!!!!\n";
    //setfloor(0);
    }
    }

    int Elevator::getfloor(){ //get current floor
    cout<<"Elevator::getfloor->Currentfloor is "<<cfloor<<endl;
    return cfloor;
    }

    void Elevator::setfloor(int floor){ //sets the floor
    cfloor = floor;
    cout<<"Elevator::setfloor->cfloor is "<<cfloor<<" floor is "<<floor<<endl;

    }

    void Elevator::open(){ //opens door

    cout<<"Elevator::open->Open invoked"<<endl;
    cout<<"Elevator::open->cdoor value is "<<cdoor<<endl;
    if(cdoor==0){ //checks condition
    cout<<"Elevator::open->If this msg shows, means its running under cdoor is 0 condition"<<endl;
    cout<<"Elevator::open->Currently door is closed so we open it\n";
    setdoor(1);
    cout<<"Door opened\n";
    }
    else {
    cout<<"Elevator::open->If this msg shows, means its running under cdoor is 1 condition"<<endl;
    cout<<"Elevator::open->Currently door is opened so we can't open it again!\n";
    }
    }

    void Elevator::close(){ //closes door
    cout<<"Elevator::close->Closing invoked"<<endl;
    cout<<"Elevator::close->cdoor value is "<<getdoor()<<endl;
    if(cdoor==1){
    cout<<"Elevator::close->If this msg shows, means its running under cdoor is 1 condition"<<endl;
    cout<<"Elevator::close->Currently door is opened so we close it\n";
    setdoor(0);
    cout<<"Elevator::close->Door closed\n";
    }
    else {
    cout<<"Elevator::close->This msg shows that cfloor is 0 and door is closed."<<endl;
    cout<<"Elevator::close->Currently door is closed so we can't close it again!\n";
    }
    }

    int Elevator::getdoor(){ //gets door status
    return cdoor;
    }

    void Elevator::setdoor(int door){ //sets door status
    cdoor = door;
    cout<<"Elevator::setdoor->cdoor is "<<cdoor<<" door is "<<door<<endl;

    }

    void Elevator::bell(){ //bell and light
    cout<<"Elevator::bell->Ding\n";
    pause();
    }

    int Elevator::pause(void){

    getche(); //this is to wait for a key to be pressed
    return 0;
    }




    #include <iostream.h>
    #include <stdlib.h>
    #include "elevator.h"
    #include <conio.h>
    #include <time.h>

    class random1 : public Elevator{ //inherit elevator class to use its functions like elevator::up()...
    public:
    int showtme();
    int ctme();
    int cact();
    void reset();
    void rnd(int a);
    void tme(int rnum);
    void checker(int perlvl, int elelvl);
    void act(int state);


    private:
    int curtime;
    int rnum;
    int state;
    int perlvl;
    int elelvl;

    };



    #include "random1.h"

    int random1::showtme(){
    return rnum;}

    void random1::rnd(int a){
    rnum = rand()%a;
    cout<<"Random::rnd->rnum is "<<rnum<<endl;

    }

    void random1::reset(){
    curtime=0;
    }

    void random1::tme(int rnum){
    curtime=curtime+rnum;
    cout<<"Random::tme->Current Time is"<<curtime<<endl;
    //return 0;
    }

    int random1::ctme(){
    return curtime;}

    void random1::checker(int perlvl, int elelvl){
    if(perlvl==0 && elelvl==1){
    cout<<"Random::checker->state 1->person is on first floor\n";
    cout<<"Random::checker->state 1->elevator is on second floor so we are calling it down\n";
    state = 1;}

    else if (perlvl ==0 && elelvl==0){
    cout<<"Random::checker->state 2->elevator is on first floor\n";
    state = 2;}

    else if (perlvl==1 && elelvl==0){
    cout<<"Random::checker->state 3->person is on second floor\n";
    cout<<"Random::checker->state 3->elevator is on first floor so we are calling it up\n";
    state = 3;}

    else if (perlvl==1 && elelvl==1){
    cout<<"Random::checker->state 4->elevator is on second floor\n";
    state = 4;}

    }

    int random1::cact(){
    cout<<"Random::cact->State is "<<state<<endl;
    return state;
    }

    void random1::act(int state){
    cout<<"Random::act->state is "<<state<<endl;
    switch(state){
    case 1: Elevator::down();
    Elevator::up();
    break;
    case 2: Elevator::up();
    break;
    case 3: Elevator::up();
    Elevator::down();
    break;
    case 4: Elevator::down();
    break;
    }
    }



    int main(){
    Elevator e; //creates elevator object
    random1 o;
    srand(time(NULL)); // seeds the random number generator with time


    int r;
    int i;
    int l;
    int perlvl, elelvl;

    cout<<"Main->Initiating Reset\n";
    e.reset(); //resets the elevator
    o.reset();

    for(i=0;i<60;){
    o.rnd(15);
    r = o.showtme(); //this gets the value of rnum from random1 class
    o.tme(r);
    i = o.ctme();
    cout<<"Main->i value is "<<i<<endl;
    o.rnd(2); // used to generate a number of 0 or 1 which is to determine the lvl person is on
    perlvl = o.showtme();
    cout<<"Main->Person lvl is "<<perlvl<<endl;

    elelvl = e.getfloor();
    cout<<"Main->Elelvl is "<<elelvl<<endl;
    o.checker(perlvl, elelvl); //checks condition
    l=o.cact();
    o.act(l); //action to perform on each condition
    cout<<"Main->value of rnum is"<<r<<endl;



    }
    return 0;
    }

  2. #2
    Registered User Strider's Avatar
    Join Date
    Aug 2001
    Posts
    149
    Add a constructor to initialize your data members:
    Code:
    Elevator::Elevator() : door(0),
    					floor(0),
    					cdoor(0),
    					cfloor(0)
    {
    }
     // and
    
    random1::random1() : curtime(0), 
    					rnum(0),
    					state(0),
    					perlvl(0),
    					elelvl(0)
    {
    }
    Also, keep your data members in the Elevator class private:
    Code:
    private:
    int door; 
    int floor; 
    int cfloor; //current floor 
    int cdoor; //current door status
    Because the data was never set unless you specifically called a reset function, it was not always initialized properly prior to access. This should cear it up for you.

    David
    One Ring to rule them all, One Ring to find them,
    One Ring to bring them all and in the darkness bind them
    In the Land of Mordor where the Shadows lie.

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