sfml - vector[0].getPosition() returns 0 - c++

Question

I was making a simple snake game but when I tried moving a part of my snake
it went to 0,0.
I keep all parts of my snake inside a vector.
But when I do something like
vector[0].getPosition()
//(In my code: snakeParts[0].getPosition())
It just returns 0,0.
I also don't get any error whilst compiling.
Here's my code:
#include <SFML/Graphics.hpp>
#include <iostream>
#include <string>
#include <unistd.h>
#include <vector>
using namespace std;
sf::RenderWindow App(sf::VideoMode(854, 480), "Snake");
sf::RectangleShape snake;
sf::RectangleShape snake2;
vector<sf::RectangleShape> snakeParts;
string movingDirection = "Right";
int updatePos() {
snakeParts[1].setPosition(snakeParts[0].getPosition()); //Where my problem lies
if (movingDirection == "Left") {
snake.move(-32,0);
}
else if (movingDirection == "Right") {
snake.move(32,0);
}
else if (movingDirection == "Up") {
snake.move(0,-32);
}
else if (movingDirection == "Down") {
snake.move(0,32);
}
//for (int i=0; i<snakeParts.size(); i++) {
//int target = snakeParts.size()-i;
}
int main()
{
snake.setSize(sf::Vector2f(32, 32));
snake.setFillColor(sf::Color::Green);
snake2.setSize(sf::Vector2f(32, 32));
snake2.setFillColor(sf::Color::Red);
snakeParts.push_back(snake);
snakeParts.push_back(snake2);
while (App.isOpen())
{
sf::Event event;
while (App.pollEvent(event))
{
if (event.type == sf::Event::Closed)
App.close();
if (sf::Keyboard::isKeyPressed(sf::Keyboard::Left)) {
movingDirection = "Left";
}
else if (sf::Keyboard::isKeyPressed(sf::Keyboard::Right)) {
movingDirection = "Right";
}
else if (sf::Keyboard::isKeyPressed(sf::Keyboard::Down)) {
movingDirection = "Down";
}
else if (sf::Keyboard::isKeyPressed(sf::Keyboard::Up)) {
movingDirection = "Up";
}
}
usleep(100000);
//cout << movingDirection << endl;
updatePos();
App.clear();
App.draw(snake);
App.draw(snake2);
App.display();
}
return 0;
}
I think it's something to do with pointers?
But I wouldn't know how I would fix that...

Answer 1

Dump those global snakeN variables! Are you going to declare everything up to snake100 if you want to have 100 cells? Your vector is storing copies (those are left untouched on (0, 0)), on which you should be performing all the logic.
Make all other global variables local to a function or member of a class and use function parameters where needed.
movingDirection should be an enum.
updatePos with its current signature should return something.