Java中的 AbstractSequentialList clear() 方法与示例

Java中AbstractSequentialList的clear()方法用于从列表中删除所有元素。此调用返回后，列表将为空。

句法：

public void clear()

参数：此函数没有参数。

返回：该方法不返回任何值。它删除列表中的所有元素并使其为空。

下面的示例说明了 AbstractSequentialList.clear() 方法：

示例 1：

// Java code to demonstrate the working of
// clear() method in AbstractSequentialList
  
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
    {
        // creating an AbstractSequentialList
        AbstractSequentialList arr
            = new LinkedList();
  
        // using add() to initialize values
        // [1, 2, 3, 4]
        arr.add(1);
        arr.add(2);
        arr.add(3);
        arr.add(4);
  
        // list initially
        System.out.println("The list initially: "
                           + arr);
  
        // clear function used
        arr.clear();
  
        // list after clearing all elements
        System.out.println("The list after "
                           + "using clear() method: "
                           + arr);
    }
}

输出：

The list initially: [1, 2, 3, 4]
The list after using clear() method: []

示例 2：

// Java code to demonstrate the working of
// clear() method in AbstractSequentialList
  
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
    {
        // creating an AbstractSequentialList
        AbstractSequentialList arr
            = new LinkedList();
  
        // using add() to initialize values
        // [Geeks, For, ForGeeks, GeeksForGeeks]
        arr.add("Geeks");
        arr.add("For");
        arr.add("ForGeeks");
        arr.add("GeeksForGeeks");
  
        // list initially
        System.out.println("The list initially: "
                           + arr);
  
        // clear function used
        arr.clear();
  
        // list after clearing all elements
        System.out.println("The list after "
                           + "using clear() method: "
                           + arr);
    }
}

输出：

The list initially: [Geeks, For, ForGeeks, GeeksForGeeks]
The list after using clear() method: []