Java 数组复制clone方法实现详解

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

以上是 Java 数组复制clone方法实现详解 的全部内容, 来源链接: utcz.com/z/344218.html

回到顶部