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Java 陣列複製clone方法實現詳解

這篇文章主要介紹了Java 陣列複製clone方法實現詳解,文中通過示例程式碼介紹的非常詳細,對大家的學習或者工作具有一定的參考學習價值,需要的朋友可以參考下

一、原始碼

public class Test1 {
  public static void main(String[] args) {
    // Student[] arrs = new Student[] { new Student() { id = "22" } }; C# 可以簡寫法,Java不支援
    Student[] arrs = new Student[1];
    Student st = new Student();
    st.id = 12;
    st.name = "qwe";
    arrs[0] = st;
    Student[] arrss = arrs.clone();
    System.out.println(arrs == arrss);
    System.out.println(arrs.equals(arrss));
    arrss[0].id = 56;
    for (int i = 0; i < arrs.length; i++) {
      System.out.println(arrs[i].id + arrs[i].name);
    }
    for (int i = 0; i < arrss.length; i++) {
      System.out.println(arrss[i].id + arrss[i].name);
    }
    System.out.println("-------------自定義物件型別陣列clone-------------");

    Student[] arrst1 = new Student[1];
    Student st1 = new Student();
    st1.id = 162;
    st1.name = "qkkj";
    arrst1[0] = st1;
    Student[] arrst2 = arrst1;
    System.out.println(arrst1 == arrst2);
    System.out.println(arrst1.equals(arrst2));
    arrst2[0].id = 996;
    for (int i = 0; i < arrst1.length; i++) {
      System.out.println(arrst1[i].id + arrst1[i].name);
    }
    for (int i = 0; i < arrst2.length; i++) {
      System.out.println(arrst2[i].id + arrst2[i].name);
    }
    System.out.println("-------------自定義物件型別陣列= 賦值-------------");

    var arr1 = new String[] { "we","dfeffg" };
    var arr = arr1.clone();
    System.out.println(arr1 == arr);
    System.out.println(arr1.equals(arr));
    arr[1] = "ddddddddddddddd";
    for (int i = 0; i < arr.length; i++) {
      System.out.println(arr[i]);
    }
    for (int i = 0; i < arr1.length; i++) {
      System.out.println(arr1[i]);
    }
    System.out.println("------------字串陣列clone--------------");

    var arr11 = new String[] { "we","dfeffg" };
    var arr111 = arr11;
    System.out.println(arr111 == arr11);
    System.out.println(arr111.equals(arr11));
    arr111[1] = "ddddddddddddddd";
    for (int i = 0; i < arr11.length; i++) {
      System.out.println(arr11[i]);
    }
    for (int i = 0; i < arr111.length; i++) {
      System.out.println(arr111[i]);
    }
    System.out.println("------------字串陣列=賦值--------------");

    var arr2 = new int[] { 232,45 };
    var arr3 = arr2.clone();
    System.out.println(arr2 == arr3);
    System.out.println(arr2.equals(arr3));
    arr3[1] = 4444;
    for (int i = 0; i < arr2.length; i++) {
      System.out.println(arr2[i]);
    }
    for (int i = 0; i < arr3.length; i++) {
      System.out.println(arr3[i]);
    }
    System.out.println("------------數字型別陣列clone--------------");

    var arr4 = new int[] { 23432,44455 };
    var arr5 = arr4;
    System.out.println(arr4 == arr5);
    System.out.println(arr4.equals(arr5));
    arr4[1] = 6666;
    for (int i = 0; i < arr4.length; i++) {
      System.out.println(arr4[i]);
    }
    for (int i = 0; i < arr5.length; i++) {
      System.out.println(arr5[i]);
    }
    System.out.println("------------數字型別陣列=賦值-----------------");
  }
}

class Student {
  public int id;
  public String name;
}

二、執行結果

false
false
56qwe
56qwe
-------------自定義物件型別陣列clone-------------
true
true
996qkkj
996qkkj
-------------自定義物件型別陣列= 賦值-------------
false
false
we
ddddddddddddddd
we
dfeffg
------------字串陣列clone--------------
true
true
we
ddddddddddddddd
we
ddddddddddddddd
------------字串陣列=賦值--------------
false
false
45
4444
------------數字型別陣列clone--------------
true
true
6666
6666
------------數字型別陣列=賦值-----------------

三、結果分析

  1.clone複製,對於陣列本身而言,它的元素是引用型別(字串除外)的時候,本來陣列每個元素中儲存的就是物件的引用,所以,拷貝過來的陣列自然而言也是物件的引用,所以對於陣列物件元素而言,它又是淺拷貝;

  2.clone複製,對於引用型別(字串除外),改變其中一箇中的值,會影響另外一個值,相當於“淺拷貝”;

  3.clone複製,對於值型別、字串,改變其中一箇中的值,不會影響另外一個值,相當於“深拷貝”;

  4.等號復值後修改一個後會影響另一個

以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支援我們。