void add(int index, E element) //Inserts the specified element at the specified position in this list.在给定的位置添加一个元素 ListIterator<E> listIterator(int index) //Returns a list-iterator of the elements in this list (in proper sequence), starting at the specified position in the lis...
4.4、add(int index, E element) /** * Inserts the specified element at the specified position in this * list. Shifts the element currently at that position (if any) and * any subsequent elements to the right (adds one to their indices). * @param index index at which the specified elem...
banana]//Adding a new element at index position 1arraylist.add(1,"grapes");// [apple, grapes, banana]//Adding multiple elements element at index position 0arraylist.add(0,Arrays.asList("date","guava"));// [date, guava, apple, grapes, banana] ...
一:add(index, element)和set(index, element)插入集合对比 代码 publicclassTestList {privatestaticList<Integer>testList;publicstaticvoidmain(String[] args) { initList();//初始化listSystem.out.println("initList="+testList.toString()); System.out.println("initList.size="+testList.size()); add...
JavaList——list.add（index,element）和list.set（in。。。add(index, element)含义：在集合索引为index的位置上增加⼀个元素element，集合list改变后list.size()会增加1 ⽤法 testList.add(index, element);set(index, element)含义：在集合索引为index的位置上改变⼀个元素，改变后的元素为element，集合...
Java ArrayList add(int index, E element)和set(int index, E element)两个方法的说明 一般使用List集合,估计都是使用这个ArrayList,一般呢也就是简单遍历数据和存储数据。 很少使用到add(int index, E element)和set(int index, E element)两个方法。
assertEquals(resultList.get(3), (Double)9.9); }Copy 5. Conclusion In this short article, we’ve seen how to add a single element to aStream,be it at the beginning, at the end, or at a given position. Prepending an element works for anyStreamand technically works to append to the end...
Inserts the specified element at the specified position in this list. Shifts the element currently at that position (if any) and any subsequent elements to the right (adds one to their indices). 而赋值是这个,同理请记得RTFM。 第三,如果你需要的是保证初始的容量足够大,用 带参数的构造函数 ...
This one list object is biting me in the butt.. Any time I try to add an element to it, it produces this: Caused by: java.lang.UnsupportedOperationException at java.util.AbstractList.add(AbstractList.java:148) at java.util.AbstractList.add(AbstractList.java:108) ...
因此新的方法更适合容易出现异常条件的情况。 peek,element区别: element() 和 peek() 用于在队列的头部查询元素。与 remove() 方法类似,在队列为空时, element() 抛出一个异常,而 peek() 返回 null。