Your script seems to be a mix of unity-script (or javascript as it actually called) and C#. The compiler will compile it as one of them depending on the extension: *.cs for C# and *.js for javascript. The way these different languages handle variables is different, as a result, your code won’t compile. I don’t know what type of script you are using, but here is a solution (make sure you put it in a C# file):
using UnityEngine;
using System.Collections;
public class Player : MonoBehaviour
{
/* Moved this part out of the Start method,
* as I assume it is supposed to be used throughout the entire class.
* The "[SerializeField]" tag is used to display the variables in the inspector.
*/
[SerializeField]
private float speed = 6.0f;
[SerializeField]
private float jumpSpeed = 8.0f;
[SerializeField]
private float gravity = 20.0f;
// Use this for initialization
void Start () {}
// Update is called once per frame
void Update () {}
}
This code won’t do anything particular, as nowhere is specified that it will do something.