I Can

1.定义一个小计算器类。

     class Calculate{
//加法运算
/*
int add(int number1, int number2){//在这里定义的参数称为“形参”。形参属于局部变量。
int result = number1 + number2;

return result;
}*/


int add(int... numbers){//使用可变参数
//System.out.println(numbers.length);
int result = 0;
for(int i=0;i<numbers.length;i++){
result = result + numbers[i];
}


return result;
}


//对两个整数值进行交换
void swap(int number1, int number2){
int temp;
temp = number1;
number1 = number2;
number2 = temp;
}


void swap(int[] numbers){
int temp;
temp = numbers[0];
numbers[0] = numbers[1];
numbers[1] = temp;
}
}




public class Demo4{
public static void main(String[] args){
//int a = 3, b = 5;


Calculate cal = new Calculate();

//cal.add();
System.out.println(cal.add());
System.out.println(cal.add(1));
System.out.println(cal.add(1,1));
System.out.println(cal.add(1,1,1));


//int addResult = cal.add(a, b);//这里传进去的a和b称为”实参“
//System.out.println(addResult);//输出结果：8
//System.out.println(a);
/*
System.out.println("交换方法调用前：a=" + a + ",b=" + b);//a=3,b=5
cal.swap(a,b);
System.out.println("交换方法调用后：a=" + a + ",b=" + b);//a=5,b=3
*/
/*
int[] intArray = {3, 5};
System.out.println("交换方法调用前：" + intArray[0] + "," + intArray[1]);
cal.swap(intArray);
System.out.println("交换方法调用后：" + intArray[0] + "," + intArray[1]);
*/
}
}