Java 示例 - 删除元素

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  问题描述

  如何删除数组的元素？
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  解决方案

  以下示例显示了如何从数组中删除元素。

  
  import java.util.ArrayList;
  public class Main {
     public static void main(String[] args) {
        ArrayList objArray = new ArrayList();
        objArray.clear();
        objArray.add(0,"0th element");
        objArray.add(1,"1st element");
        objArray.add(2,"2nd element");
        System.out.println("Array before removing an element"+objArray);
        objArray.remove(1);
        objArray.remove("0th element");
        System.out.println("Array after removing an element"+objArray);
     }
  }
  

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  结果

  上面的代码示例将产生以下结果。

  
  Array before removing an  element[0th element, 1st element, 2nd element]
  Array after removing an element[2nd element]
  

  数组移除的另一个示例

  
  import java.util.ArrayList;
  public class ArrayListDemo {
     public static void main(String[] args) {
        ArrayList<Integer> arr = new ArrayList<Integer>(5);
        arr.add(20);
        arr.add(15);
        arr.add(30);
        arr.add(45);
        
        System.out.println("Size of list: " + arr.size());
        for (Integer number : arr) {
           System.out.println("Number = " + number);
        } 
        arr.remove(2);
        System.out.println("Now, Size of list: " + arr.size());
        
        for (Integer number : arr) {
           System.out.println("Number = " + number);
        } 
     }
  }   
  

  上面的代码示例将产生以下结果。

  
  Size of list: 4
  Number = 20
  Number = 15
  Number = 30
  Number = 45
  Now, Size of list: 3
  Number = 20
  Number = 15
  Number = 45