state_entry() when is this needed

Working on this script /54/dd/230130/1.html#post1802926 made me realize that state_entry() is sometimes needed for a change of state, but I don't understand why or when it is needed. Can anyone shed some light on this?

For Example this wiki example under "states" does not use state_entry() in the default state.

default
{
    touch_start(integer a)
    {
        state hello;
    }
}

state hello
{
    state_entry()
    {
        llOwnerSay("Hello");
        state default;
    }
    state_exit()
    {
        llOwnerSay("Goodbye");
    }
}

And this example under state_entry() does use it.

default
{
    state_entry()
    {
        llSay(0, "Hello, Avatar!");
    }
}

As best I can guess, if you want the script to do something as soon as it enters a state you need to use state_entry(), otherwise the script waits for an event to trigger whatever action is in that state. Is that it?

[/php]

Yes.

Actually it is more then just that. In state entry you can define your global variables that will not change, pos = llGetPos() for instance, or owner = llGetOwner(), so that you do not make the server repeatedly have to get the same info. Also a good place to define listen handles etc.

Sometimes you will find that you need to set a global variable to an empty string or list, if you don't want to carry the info over from another state by declaring it string = "" etc.

If you need a listen as soon as the script is running then state entry would be the place to call it.

Many, many, many, many uses.

I think at one point the compiler didn't like not having it in the default state....

only use the events you need, states must have at least one event to compile