ArrayList list = new ArrayList();//底层Object[] elementData初始化为{}.并没创建长度为10的数组 list.add(123);//第一次调用add()时,底层才创建了长度10的数组,并将数据123添加到elementData[0] ... 后续的添加和扩容操作与jdk 7 无异。 小结:jdk7中的ArrayList的对象的创建类似于单例的饿汉式,而jdk8...
30. Which of the following is a superclass of every class in Java? a) ArrayList b) Abstract class c) Object class d) String View Answer31. What will be the output of the following Java code?class Output { public static void main(String args[]) { double x = 3.14; int y = (...