Java Utililty Methods Collection First

Object[] obj = collection.toArray();
if (obj.length > 0) {
    return obj[0];
} else {
    return null;

if (size(collection) > 0) {
    return (T) collection.iterator().next();
return null;

if (items != null && items.size() > 0) {
    return items.iterator().next();
return null;

Iterator<? extends E> iterator = collection.iterator();
if (iterator.hasNext()) {
    return iterator.next();
return alternative;

ArrayList<T> list = new ArrayList<>(collection);
return list.isEmpty() ? null : list.get(0);

final T notFound = null;
return isEmpty(collection) ? notFound : collection.iterator().next();

List<Double> filteredValues = filterNulls(values);
return filteredValues.size() > 0 ? filteredValues.get(0) : null;

if (isEmpty(collection)) {
    return null;
Iterator<E> iterator = collection.iterator();
if (iterator.hasNext()) {
    return iterator.next();
throw new IllegalStateException("Should not happen");
...

• OrderedSet::first() : T
• Sequence::first() : T

if (self.isEmpty()) {
    return null; 
return self.iterator().next();

return c.iterator().next();