Java中的 AbstractSequentialList set(int, Object) 方法及示例

Java AbstractSequentialList的set()方法用于将使用 AbstractSequentialList 类创建的列表中的任何特定元素替换为另一个元素。这可以通过在 set() 方法的参数中指定要替换的元素的位置和新元素来完成。

句法：

public E set(int index, Object element)

参数：此函数接受两个参数，如上述语法所示，如下所述。

• index ：这是整数类型，指的是要从列表中替换的元素的位置。
• element ：它将替换现有元素的新元素，并且与列表具有相同的对象类型。

返回值：该方法从列表中返回被新值替换的前一个值。

异常：此方法抛出以下异常：

• UnsupportedOperationException ：如果此列表不支持设置操作
• ClassCastException : 如果指定元素的类阻止它被添加到这个列表中
• NullPointerException : 如果指定元素为 null 并且此列表不允许 null 元素
• IllegalArgumentException : 如果指定元素的某些属性阻止它被添加到此列表中
• IndexOutOfBoundsException : 如果索引超出范围 (index = size())

下面的程序说明了Java.util.AbstractSequentialList.set() 方法：

示例 1：

// Java code to illustrate set()
  
import java.io.*;
import java.util.*;
  
public class AbstractSequentialListDemo {
    public static void main(String args[])
    {
        // Creating an empty AbstractSequentialList
        AbstractSequentialList list
            = new LinkedList();
  
        // Use add() method to add elements in the list
        list.add("Geeks");
        list.add("for");
        list.add("Geeks");
        list.add("10");
        list.add("20");
  
        // Displaying the linkedlist
        System.out.println("AbstractSequentialList:"
                           + list);
  
        // Using set() method to replace Geeks with GFG
        System.out.println("The Object that is replaced is: "
                           + list.set(2, "GFG"));
  
        // Using set() method to replace 20 with 50
        System.out.println("The Object that is replaced is: "
                           + list.set(4, "50"));
  
        // Displaying the modified linkedlist
        System.out.println("The new AbstractSequentialList is:"
                           + list);
    }
}

输出：

AbstractSequentialList:[Geeks, for, Geeks, 10, 20]
The Object that is replaced is: Geeks
The Object that is replaced is: 20
The new AbstractSequentialList is:[Geeks, for, GFG, 10, 50]

示例 2：演示 IndexOutOfBoundException

// Java code to illustrate set()
  
import java.io.*;
import java.util.*;
  
public class AbstractSequentialListDemo {
    public static void main(String args[])
    {
        // Creating an empty AbstractSequentialList
        AbstractSequentialList list
            = new LinkedList();
  
        // Use add() method to add elements in the list
        list.add("Geeks");
        list.add("for");
        list.add("Geeks");
        list.add("10");
        list.add("20");
  
        // Displaying the linkedlist
        System.out.println("AbstractSequentialList:"
                           + list);
  
        // Using set() method to replace 10th with GFG
        // and the 10th element does not exist
        System.out.println("Trying to replace 10th "
                           + "element with GFG");
  
        try {
            list.set(10, "GFG");
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}

输出：

AbstractSequentialList:[Geeks, for, Geeks, 10, 20]
Trying to replace 10th element with GFG
java.lang.IndexOutOfBoundsException: Index: 10, Size: 5