Java Utililty Methods List First Item

List of utility methods to do List First Item

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Description

The list of methods to do List First Item are organized into topic(s).

Method

ListaddFirst(List list, Object values)
add First 
list.add(0, values);
return list;
voidaddFirstAndRemoveOldIfNeed(List dest, List src)
add First And Remove Old If Need 
if (dest == null) {
    return;
if (src == null || src.isEmpty()) {
    return;
removeDuplicate(dest, src);
dest.addAll(0, src);
...
List

cons(P first, List list)
cons 
List<P> builder = new ArrayList<>(list.size() + 1);
builder.add(first);
builder.addAll(list);
return builder;
booleanequalLists(List first, List second)
equal Lists 
if (first == null) {
    return second == null;
} else if (second == null) {
    return first == null;
if (first.size() == second.size()) {
    for (int i = 0; i < first.size(); i++) {
        if (!equalObjects(first.get(i), second.get(i))) {
...
voidexpectedOrder(List src, Object first, Object second)
expected Order 
int firstIndex = src.indexOf(first);
int secondIndex = src.indexOf(second);
if (firstIndex >= secondIndex) {
    throw new AssertionError("Wrong order for [" + first + ", " + second + "] in " + src);
ListextractFirst(int numberToExtract, List list)
extract First 
List<T> topList = new ArrayList<T>();
for (int i = 0; i < numberToExtract && i < list.size(); i++) {
    topList.add(list.get(i));
return topList;
Tfirst(final List list)
Gets the first element of the given list, or null if none. 
if (list == null || list.size() == 0)
    return null;
return list.get(0);
Tfirst(final List list, final int oridinal)
Returns the first ordinal element in the list. 
final int size = list.size() - 1;
if (size >= oridinal) {
    return list.get(oridinal);
return null;
Tfirst(final List t)
Returns first item in List . 
return t != null && !t.isEmpty() ? t.get(0) : null;
Kfirst(List list)
first 
if (isNull(list)) {
    return null;
return list.get(0);