My cube can't stop jumping

Questions & Answers
1

If I press the jump button the cube jumps, but if I press the jump button again while its still falling(in the air) the cube will still jump. How do I make the cube only jump once from the floor and not be able to jump again in the air?

Thanks for reading and helping in advance.

public class Player : MonoBehaviour {

// Use this for initialization
void Start () {}	
// Update is called once per frame
void Update () {    
if (Input.GetKeyDown ("space")){
 transform.Translate(Vector3.up * 260 * Time.deltaTime, Space.World);
}
}

}

2

You need a way to tell when the cube is touching the floor, when the cube isn’t touching the floor, don’t let it jump.

Easiest method is probably to check Collisions on the cube’s rigidbody, after jumping, if it hasn’t collided with the floor, don’t let the player make it jump again.

Example code in c# (not tested)

void OnCollisionEnter(Collision colided)
{
   if(colided.gameObject.tag == "floor")
   {
      allowJump = true;
   }
}

And in your jump function, set allowJump to false.
You’ll need to create a boolean value called allowJump.
Edit: You also need to tag your floors as “floor”