Returning early from a function

I'm having a mental block, can someone remind me what the correct term for returning early from a function is, i.e.

private MyOb开发者_StackOverflow中文版ject DoSomeStuff(string myValue)
{
    //What is this called?!?!?
    if(myValue == string.Empty)
        return null;

    MyObject obj = new MyObject();
    obj.Value = myValue;
    return obj;
}

---

I believe it's called a guard clause.

---

I would potentially call this an Interrupt. Or, simply, and Early Return. Break might work, too.

---

I would call it a "precondition test".