Why do I see floats set without values in tutorials?

In a number of tutorials i have seen people assign float without values for their code, i am currently doing the Unity Learn scripting tutorials, one of the lines of code adds a force to the bullet which Time.deltaTime * bulletSpeed; they set the bullet speed variable to : float; but with no value. In new to code so if someone could help me that would be much appreciated.

Here’s the code, the variable is at the top and the line of code I talked about is at the bottom.

`public var bulletPrefab : Rigidbody;
public var firePosition : Transform;
public var bulletSpeed : float;

private var inventory : Inventory;

function Awake ()
{
inventory = GetComponent(Inventory);
}

function Update ()
{
Shoot();
}

function Shoot ()
{
if(Input.GetButtonDown(“Fire1”) && inventory.myStuff.bullets > 0)
{
var bulletInstance : Rigidbody = Instantiate(bulletPrefab, firePosition.position, firePosition.rotation);
bulletInstance.AddForce(firePosition.forward * bulletSpeed);
inventory.myStuff.bullets–;
}
}`

A good question - this reference page should answer it for you:

http://docs.unity3d.com/Documentation/ScriptReference/index.Member_Variables_26_Global_Variables.html