Digging technique counter - unity3d

Question

I'm making and game which has digging as it's feature so I need timer which will count exact float (in seconds) and then destroy gameObject. This is what I tried now but it's freezing unity:
function Update()
{
if (Input.GetMouseButtonDown(0))
{
digTime = 1.5; // in secounds
}
while (!Input.GetMouseButtonUp(0)) // why is this infinite loop?
{
digtime -= Time.deltaTime;
if (digtime <= 0)
{
Destroy(hit.collider.gameObject);
}
}

Answer 1

Here is a basic example how you can check if player has clicked for a certain time period.
#pragma strict
// This can be set in the editor
var DiggingTime = 1.5;
// Time when last digging started
private var diggingStarted = 0.0f;
function Update () {
// On every update were the button is not pressed reset the timer
if (!Input.GetMouseButton(0))
{
diggingStarted = Time.timeSinceLevelLoad;
}
// Check if the DiggingTime has passed from last setting of the timer
if (diggingStarted + DiggingTime < Time.timeSinceLevelLoad)
{
// Do the digging things here
Debug.Log("Digging time passed");
// Reset the timer
diggingStarted = Time.timeSinceLevelLoad;
}
}
It is firing every DiggingTime of seconds even the player is holding the button down. If you want that the player needs to release the button and press again one solution is to add Boolean telling if the timer is on or not. It can be set true on GetMouseButtonDown and false on GetMouseButtonUp.

Answer 2

Update function is called every frame. If you add a while loop inside this function waiting for the mouseButtonUp, you'll freeze Unity for sure.
You don't need the while loop. Just check GetMouseButtonUp without while loop.
EDIT
This is the Update function:
void Update ()
{
if ( Input.GetMouseButtonDown( 0 ) )
{
digTime = 1.5f;
}
else if ( Input.GetMouseButton( 0 ) )
{
if ( digTime <= 0 )
{
Destroy( hit.collider.gameObject );
}
else
{
digTime -= Time.deltaTime;
}
}
}
Minor controls should be added to avoid destroying gameObject several times, but this is the idea to proceed