ArrayList源碼code
public boolean add(E e) { ensureCapacityInternal(size + 1); // Increments modCount!! elementData[size++] = e; return true; }
LinkedList源碼ci
public boolean add(E e) { linkLast(e); return true; }
Vector源碼element
public synchronized boolean add(E e) { modCount++; ensureCapacityHelper(elementCount + 1); elementData[elementCount++] = e; return true; }