public class Swap
{
    public static void swap(int a, int b)
    {
        int temp = a;
        a = b;
        b = temp;
    }

    public static void main(String[] args)
    {
        int x = 3;
        int y = 4;

        Swap.swap(x, y);

        System.out.println(x);//3
        System.out.println(y);//4

        System.out.println("111111111111");

        int temp = x;
        x = y;
        y = temp;

        System.out.println(x);//4
        System.out.println(y);//3

        System.out.println("2222222222222");
        
        int a = 3;
        int b = 4;

        a = a + b;
        b = a - b;
        a = a - b;
        
        System.out.println(a);//4
        System.out.println(b);//3
    }
}

public class Swap2
{
    public static void swap(char[] ch, char c)
    {
        ch[0] = 'B';
        c = 'D';
    }

    public static void main(String[] args)
    {
        char[] ch = {'A', 'C'};
        swap(ch, ch[1]);
        for(int i = 0; i < ch.length; i++)
        {
            System.out.print(ch[i] + " ");//B C
        }
    }
}

public class Swap3
{
    public static void swap(int[] i)
    {
        int temp = i[0];
        i[0] = i[1];
        i[1] = temp;
    }

    public static void main(String[] args)
    {
        int[] i = {1, 2};

        swap(i);

        System.out.println(i[0]);//2
        System.out.println(i[1]);//1
    }
}

public class ArrayTest6
{
    public static void main(String[] args)
    {
        I[] i = new I[2];

        i[0] = new C();
        i[1] = new C();

        int[] a = new int[] {1, 2, 3};//原生数据类型直接赋值

        I[] b = new I[]{new C(), new C()};//等价于I[] i = new I[2];    i[0] = new C();  i[1] = new C();
    }
}

interface I
{

}

class C implements
{

}

public class ArrayEqualsTest
{
    public static boolean isEquals(int[] a, int[] b)
    {
        if(a == null || b == null)
        {
            return false;
        }

        if(a.length != b.length)
        {
            return false;
        }

        for(int i = 0; i < a.length; i++)
        {
            if(a[i] != b[i])
            {
                return false;
            }   
        }
    
        return true;
    }

    public static void main(String[] args)
    {
        int[] a = {1, 2, 3};
        int[] b = {1, 2, 3};

        System.out.println(isEquals(a, b));//true

        System.out.println(Arrays.equals(a, b));//true
    }
}