Java 程式初始化列表


在本文中,我們將瞭解如何初始化列表。列表是一種有序集合,允許我們按順序儲存和訪問元素。它包含基於索引的方法,用於插入、更新、刪除和搜尋元素。它還可以包含重複的元素。

以下是同樣的演示 −

假設我們的輸入是

Run the program

所需的輸出將是

Initializing an integer list
The elements of the integer list are: [25, 60]

Initializing a string list
The elements of the string list are: [Java, Program]

演算法

Step 1 - START
Step 2 - Declare an integer list namely integer_list and a string list namely string_list
Step 3 - Define the values.
Step 4 - Use the List<Integer> integer_list = new ArrayList<Integer>() to initialize the integer list.
Step 5 - Use List<String> string_list = new ArrayList<String>() to initialize the integer list.
Step 6 - Use the function .add() to add items to the list.
Step 7 - Display the result
Step 8 - Stop

例 1

在這裡,我們將在“main”函式下將所有操作繫結在一起。

import java.util.*;
public class Demo {
   public static void main(String args[]) {
      System.out.println("Required packages have been imported");
      System.out.println("\nInitializing an integer list");
      List<Integer> integer_list = new ArrayList<Integer>();
      integer_list.add(25);
      integer_list.add(60);
      System.out.println("The elements of the integer list are: " + integer_list.toString());
      System.out.println("\nInitializing a string list");
      List<String> string_list = new ArrayList<String>();
      string_list.add("Java");
      string_list.add("Program");
      System.out.println("The elements of the string list are: " + string_list.toString());
   }
}

輸出

Required packages have been imported

Initializing an integer list
The elements of the integer list are: [25, 60]

Initializing a string list
The elements of the string list are: [Java, Program]

例 2

在這裡,我們將操作封裝到函式中,展示面向物件的程式設計。

import java.util.*;
public class Demo {
   static void initialize_int_list(){
      List<Integer> integer_list = new ArrayList<Integer>();
      integer_list.add(25);
      integer_list.add(60);
      System.out.println("The elements of the integer list are: " + integer_list.toString());
   }
   static void initialize_string_list(){
      List<String> string_list = new ArrayList<String>();
      string_list.add("Java");
      string_list.add("Program");
      System.out.println("The elements of the string list are: " + string_list.toString());
   }
   public static void main(String args[]) {
      System.out.println("Required packages have been imported");
      System.out.println("\nInitializing an integer list");
      initialize_int_list();
      System.out.println("\nInitializing a string list");
      initialize_string_list();
   }
}

輸出

Required packages have been imported

Initializing an integer list
The elements of the integer list are: [25, 60]

Initializing a string list
The elements of the string list are: [Java, Program]

更新於: 2022 年 3 月 30 日

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