Java基礎(chǔ)學(xué)習(xí) 帶你了解Java中形參和實(shí)參的區(qū)別

public class ValueTransferTest {
	
	public static void main(String[] args) {
		
		System.out.println("***********基本數(shù)據(jù)類型：****************");
		int m = 10;
		int n = m;
		
		System.out.println("m = " + m + ", n = " + n);
		
		n = 20;
		
		System.out.println("m = " + m + ", n = " + n);
		
		System.out.println("***********引用數(shù)據(jù)類型：****************");
		
		Order o1 = new Order();
		o1.orderId = 1001;
		
		Order o2 = o1;//賦值以后，o1和o2的地址值相同，都指向了堆空間中同一個(gè)對(duì)象實(shí)體。
		
		System.out.println("o1.orderId = " + o1.orderId + ",o2.orderId = " +o2.orderId);
		
		o2.orderId = 1002;
		
		System.out.println("o1.orderId = " + o1.orderId + ",o2.orderId = " +o2.orderId);
		
	}
	
}

class Order{
	
	int orderId;
	
}

public class ValueTransferTest1 {
	public static void main(String[] args) {
		
		int m = 10;
		int n = 20;
		
		System.out.println("m = " + m + ", n = " + n);
		//交換兩個(gè)變量的值的操作
//		int temp = m ;
//		m = n;
//		n = temp;
		
		ValueTransferTest1 test = new ValueTransferTest1();
		test.swap(m, n);
		
		System.out.println("m = " + m + ", n = " + n);
		
		
	}
	
	
	public void swap(int m,int n){
		int temp = m ;
		m = n;
		n = temp;
	}
}

public class ValueTransferTest2 {
	
	public static void main(String[] args) {
		
		Data data = new Data();
		
		data.m = 10;
		data.n = 20;
		
		System.out.println("m = " + data.m + ", n = " + data.n);
		
		//交換m和n的值
//		int temp = data.m;
//		data.m = data.n;
//		data.n = temp;
		
		ValueTransferTest2 test = new ValueTransferTest2();
		test.swap(data);
		
		
		System.out.println("m = " + data.m + ", n = " + data.n);
		
	}
	
	public void swap(Data data){
		int temp = data.m;
		data.m = data.n;
		data.n = temp;
	}
	
}

class Data{
	
	int m;
	int n;

}