这篇文章主要介绍了Java 数组复制clone方法实现详解,文中通过示例代码介绍的非常详细,对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下
一、源码
- public class Test1 {
- public static void main(String[] args) {
- // Student[] arrs = new Student[] { new Student() { id = "22" } }; C# 可以简写法,Java不支持
- 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("-------------自定义对象类型数组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("-------------自定义对象类型数组= 赋值-------------");
- 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("------------字符串数组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("------------字符串数组=赋值--------------");
- 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("------------数字类型数组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("------------数字类型数组=赋值-----------------");
- }
- }
- class Student {
- public int id;
- public String name;
- }
二、运行结果
- false
- false
- 56qwe
- 56qwe
- -------------自定义对象类型数组clone-------------
- true
- true
- 996qkkj
- 996qkkj
- -------------自定义对象类型数组= 赋值-------------
- false
- false
- we
- ddddddddddddddd
- we
- dfeffg
- ------------字符串数组clone--------------
- true
- true
- we
- ddddddddddddddd
- we
- ddddddddddddddd
- ------------字符串数组=赋值--------------
- false
- false
- 45
- 4444
- ------------数字类型数组clone--------------
- true
- true
- 6666
- 6666
- ------------数字类型数组=赋值-----------------
三、结果分析
1.clone复制,对于数组本身而言,它的元素是引用类型(字符串除外)的时候,本来数组每个元素中保存的就是对象的引用,所以,拷贝过来的数组自然而言也是对象的引用,所以对于数组对象元素而言,它又是浅拷贝;
2.clone复制,对于引用类型(字符串除外),改变其中一个中的值,会影响另外一个值,相当于“浅拷贝”;
3.clone复制,对于值类型、字符串,改变其中一个中的值,不会影响另外一个值,相当于“深拷贝”;
4.等号复值后修改一个后会影响另一个