Moving

using System.Collections;
using UnityEngine;

public class MovingUpDown : MonoBehaviour {

    public float minY, maxY;
    public float speed = 1;
    public float waitTime = 1;

    delegate bool Condition();

    IEnumerator Moving ()
    {
        int direction = 1;
        while (true)
        {
            Condition isMoving;
            if (direction == 1)
                isMoving = () => { return transform.position.y < maxY; };
            else
                isMoving = () => { return transform.position.y > minY; };

            while (isMoving())
            {
                yield return null;
                transform.Translate(Vector3.up * direction * speed * Time.deltaTime);
            }

            yield return new WaitForSeconds(waitTime);
            direction *= -1;
        }
    }

    void Start ()
    {
        StartCoroutine(Moving());
    }
}