In-depth understanding of the Java List interface: Master common methods of data storage and access
Introduction:
In Java programming, the List interface is one of the commonly used data structures First, it is used to store and operate an ordered set of elements. Mastering the common methods of the List interface is one of the basic requirements for Java programming. This article will provide an in-depth understanding of the Java List interface and introduce in detail the common methods of data storage and access.
(2) Delete elements
Deleting elements is also a very common operation. The List interface provides the remove and removeAll methods to implement it. The remove method is used to delete the element at the specified position, and the removeAll method is used to delete the element in the specified collection.
(3) Modify elements
The List interface provides the set method to modify the element at the specified position. We can use the index to locate the element that needs to be modified and replace it with the new element.
(4) Get the element
The List interface provides the get method to get the element at the specified position. We can access elements in the List by index and perform further operations.
(5) Find the element
The List interface provides the indexOf and lastIndexOf methods to find the position of the element. The indexOf method is used to find the first occurrence of an element, and the lastIndexOf method is used to find the last occurrence of an element. If the element is not found, -1 is returned.
(6) Traversing elements
The List interface provides a variety of ways to traverse elements. Common ones include using for loops and using iterators. We can choose the appropriate traversal method according to specific needs.
import java.util.ArrayList; import java.util.List; public class ListDemo { public static void main(String[] args) { List<String> list = new ArrayList<>(); // 添加元素 list.add("apple"); // ["apple"] list.add("banana"); // ["apple", "banana"] list.add("orange"); // ["apple", "banana", "orange"] // 删除元素 list.remove(1); // ["apple", "orange"] // 修改元素 list.set(0, "grape"); // ["grape", "orange"] // 获取元素 String fruit = list.get(0); // "grape" // 查找元素 int index = list.indexOf("orange"); // 1 // 遍历元素 for (String item : list) { System.out.println(item); } } }
Conclusion:
Master the commonly used methods of the List interface Methods are very important for Java programming. By using the methods in the List interface, we can store, access and operate data. I hope this article can help readers better understand the Java List interface and use it flexibly in actual development.
The above is the detailed content of Java List interface analysis: master common data storage and access methods. For more information, please follow other related articles on the PHP Chinese website!