Oh yes, you are right. Then this is not dead code, just a useless null
check.
2018-07-04 19:55 GMT+07:00 Scott Palmer <swpal...@gmail.com>:
> On Jul 4, 2018, at 5:42 AM, Zheka Kozlov <orionllm...@gmail.com> wrote:
> >
> > I noticed dead code in java.util.HashMap.merge():
> >
> > public V merge(K key, V value,
> > BiFunction<? super V, ? super V, ? extends V>
> > remappingFunction) {
> > if (value == null)
> > throw new NullPointerException();
> >
> > ...
> >
> > if (value != null) { *// Condition ' value != null' is always true*
> > if (t != null)
> > t.putTreeVal(this, tab, hash, key, value);
> > else {
> > tab[i] = newNode(hash, key, value, first);
> > if (binCount >= TREEIFY_THRESHOLD - 1)
> > treeifyBin(tab, hash);
> > }
> > ++modCount;
> > ++size;
> > afterNodeInsertion(true);
> > }
> > return value;
> > }
> >
> > The code in the if branch will never be executed because `value` was
> > previously checked at the beginning of the method.
> >
> > Is this a mistake?
>
> You mean it will ALWAYS be executed. Yes, it looks to me like the ‘if’ is
> useless.
>
>
>
