用JAVA写一个函数交换两个数字

[java]
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package com.wq.swap;

[java]
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public class SwapNumbers {
public int a;
public int b;

//包装类交换
public static void swap (Integer a, Integer b) {
Integer temp = a;
a = b;
b = temp;
};

//直接交换
public static void swap (int a, int b) {
int temp = a;
a = b;
b = temp;
};

//数组
public static void swap (int[] arr) {
int temp = arr[0];
arr[0] = arr[1];
arr[1] = temp;
};

//成员对象
public void swapNum(int a, int b) {
this.a = b;
this.b = a;
};

//包装类打印
public static void print(Integer m, Integer n) {
System.out.println("m=" + m.intValue() + " n=" + n.intValue());
}
//直接打印
public static void print(int a, int b) {
System.out.println("a=" + a + " b=" + b);
}
//对象打印
public void print() {
System.out.println("a=" + this.a + " b=" + this.b);
}
//数组打印
public static void print(int[] a) {
for (int i : a) {
System.out.print(i + " ");
}
System.out.println();
}

public static void main(String[] args) {

System.out.println("------直接交换----------");
int a = 2, b = 3;

print(a,b);
swap(a, b);
print(a,b);

System.out.println("------包装类交换----------");
Integer m = new Integer(2);
Integer n = new Integer(3);

print(m,n);
swap(m, n);
print(m,n);

System.out.println("-------数组交换---------");
int[] arr = {2,3};
print(arr);
swap(arr);
print(arr);

System.out.println("-------成员变量交换---------");
print(a,b);
SwapNumbers sn = new SwapNumbers();
sn.swapNum(a, b);
sn.print();

}
}

[java]
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------直接交换----------
a=2 b=3
a=2 b=3
------包装类交换----------
m=2 n=3
m=2 n=3
-------数组交换---------
2 3
3 2
-------成员变量交换---------
a=2 b=3
a=3 b=2

[java]
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直接交换和用包装了交换都不能交换两个数的值，而采用数组交换和成员变量交换是可以做到的