"This" not available in the current context

Questions & Answers
1

Why?

using UnityEngine;
using System.Collections;

public class HillScript1 : MonoBehaviour
{
    bool direcright = true;
    public float speed = 5.0f;
	public float leftpoi = this.transform.position.x - 4;
	public float rightpoi = this.transform.position.x;
    // Use this for initialization
    void Start()
    {
		
    }

    // Update is called once per frame
    void Update()
    {
		
        if (direcright)
        {//x<1.4, x>4
            GetComponent<Rigidbody2D>().velocity = new Vector2(-speed, 0);
            if (transform.position.x <= leftpoi)
            {
                direcright = false;
            }
        }
        else {
            GetComponent<Rigidbody2D>().velocity = new Vector2(speed, 0);
            if (transform.position.x >= rightpoi)
            {
                direcright = true;
            }

        }

		}
    }
2

You cannot declare things outside of a function like that. Simple things like a boolean or public float speed = 5.0f; are fine but when you start using references, getting positions and using math operators it isn’t going to work.

Change it to this:

public float leftpoi;
public float rightpoi;

void Start()
{
     leftpoi = gameObject.transform.position.x - 4;
     rightpoi = gameObject.transform.position.x;
}

You can remove ‘this’ entirely or leave it in if you want. this.gameObject is the same as gameObject though. You can remove the gameObject too but personally I like to leave it in for clarity in case you are also using the transform from another object.