Java single column collection
1. Collection Architecture
1.1 Single column set
1.2 Two-column collection
2. Single Column Collection Architecture
3. Collection top-level interface
Contains method notes:
3.1 Collection traversal method
- iterator traversal
- Enhanced for traversal
- lambda expression traversal
3.1.1 Iterator traversal
attention to detail
3.1.2 Enhanced for traversal
3.1.3 Lambda expressions
4. List single-column collection
4.1 List
4.1.1 List Collection Features
4.1.2 Unique methods of List collection
4.1.3 List collection traversal method
- iterator traversal
- list iterator traversal
- Enhanced for traversal
- Lamdba expression traversal
- Ordinary for loop (because the List collection has an index)
public static void main(String[] args) {
List<String> stringList = new ArrayList<>();
stringList.add("1");
stringList.add("2");
stringList.add("3");
stringList.add("4");
stringList.add("5");
//1、普通for循环
for (int i = 0; i < stringList.size(); i++) {
System.out.println(stringList.get(i));
}
//2、增强for循环
for (String s : stringList) {
System.out.println(s);
}
//3、lamda表达式
stringList.forEach(s -> System.out.println(s));
//4、迭代器遍历
//获取迭代器对象，迭代器就好比是一个箭头，默认指向集合的0索引处
Iterator<String> it = stringList.iterator();
//利用循环不断的去获取集合中的每一个元素
while (it.hasNext()){
//next方法的两件事情:获取元素并移动指针
String str = it.next();
System.out.println(str);
}
// 5.列表迭代器
//获取一个列表迭代器的对象，里面的指针默认也是指向8索引的
//额外添加了一个方法:在遍历的过程中，可以添加元素
ListIterator<String> lt = stringList.listIterator();
while (lt.hasNext()){
String str = lt.next();
if ("2".equals(str)){
lt.add("6");
}
}
System.out.println(stringList);
4.1.4 Comparison of five traversal methods
4.2. ArrayList
4.3. LinkedList
Java single column collection LinkedList