如何根据下标返回相对应的元素。

[qq_39418927]

新手小白求大神指教

[李德胜1995]

[kb43446]

同志，为啥不直接在后头跟上角标呢，比如 int [] s=new int[10]; ````` System.out.println(s[2]); [size=18px][/size]

[Leslie_96]

你可以看看api文档，里面有方法的

[qq_39418927]

package exercise4;



public class TestBanking {
	public static void main(String[] args) {
		Bank b =new Bank();
		b.addCustomer("Jane" , "Smith" );
		b.addCustomer("Owen" , "Bryant");
		b.addCustomer( "Tim" , "Soley" );
		b.addCustomer("Maria", "Soley" );
		  for ( int i = 0; i < b.getNumberCustomers(); i++ ) {
		      Customer customer = b.getCustomer(i);

		      System.out.println("Customer [" + (i+1) + "] is "
					 + customer.getLastName()
					 + ", " + customer.getFirstName());
		    }
		
		
}
}

为什么我的for循环整个个没有运行一样值也赋上了 for里面什么都打印不了

[足球中国]

应该这样写 int count=b.getNumberCustomers(); for ( int i = 0; i <count ; i++ ) { Customer customer = b.getCustomer(i); System.out.println("Customer [" + (i+1) + "] is " + customer.getLastName() + ", " + customer.getFirstName()); } 你那样写每次都会调用一次函数接口。不仅效率慢了，而且看值也不直观。比如说你现在看到的应该是0

[Freefish1994]

引用 4 楼 qq_39418927 的回复:

package exercise4;



public class TestBanking {
	public static void main(String[] args) {
		Bank b =new Bank();
		b.addCustomer("Jane" , "Smith" );
		b.addCustomer("Owen" , "Bryant");
		b.addCustomer( "Tim" , "Soley" );
		b.addCustomer("Maria", "Soley" );
		  for ( int i = 0; i < b.getNumberCustomers(); i++ ) {
		      Customer customer = b.getCustomer(i);

		      System.out.println("Customer [" + (i+1) + "] is "
					 + customer.getLastName()
					 + ", " + customer.getFirstName());
		    }
		
		
}
}

为什么我的for循环整个个没有运行一样值也赋上了 for里面什么都打印不了

把Customer贴出来看下