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java - 从java中的for语句中调用方法

问题描述

我仍然是一个相当新手的程序员，所以请原谅我乱七八糟的代码。当我尝试编译以下代码时，出现错误：

The method Customer(java.lang.String, java.lang.Double) is undefined for the type Customer

我之前曾尝试在 for 语句中声明对象“s”，然后它会在程序末尾创建一个新错误，在此我再次引用对象“s”。我想知道如何解决这个问题？下面我包含了我当前的程序，以及所需的输出和Customer.class API.

API

期望的输出

import java.util.Scanner;

public class A4
{
    public static void main( String[] args )
    {
        //delcaring variables
        Scanner input = new Scanner( System.in );
        String[] name = new String[5];
        Double[] amount = new Double[5];
        Customer s = new Customer( "", 0 );
        //begining of program
        for ( int i = 0; i <= 5; i++ )
        {
            System.out.println( "please enter the name of the customer" );
            name[i] = input.next();
            System.out.println( "please enter the amount in that account" );
            amount[i] = input.nextDouble();

            s.Customer( name[i], amount[i] );
            //Customer s = new Customer(name [i],amount[i]);
        }
        System.out.println( "Search for all customers who have more than $100" );
        for ( int t = 0; t <= 5; t++ )
        {
            if ( amount[t] >= 100 )
            {
                System.out.println( name[t] );
            }
        }

        Double avgBalance = 0.0;
        for ( int r = 1; r <= 5; r++ )
        {
            avgBalance += r;
        }
        avgBalance = avgBalance / 5;

        System.out.println( "The average balance is: " + avgBalance );

        Double max = amount[1];
        for ( int j = 0; j <= 5; j++ )
        {
            if ( amount[j] > max )
            {
                max = amount[j];
            }
        }
        System.out.println( "The customer with the highest balance is: " + max );

        System.out.println( "Show all accounts after a 5% balance increase" );

        //Customer c = new Customer(name [i],amount[i]);
        for ( int e = 0; e <= 5; e++ )
        {
            //Customer c = new Customer amount[e].applyPercentageIncrease(5);
            //amount [e]=
            //applyPercentageIncrease q = new 
            s.applyPercentageIncrease( 5 );
            System.out.println( s.getName() + " has " + s.getBalance() );
        }
    }
}

更新：我已经实现了 Gtomika 的建议并且程序现在运行，但是在第一个 for 语句中，程序询问用户 6 个名称然后设置一个越界错误，我理解越界错误，但是 for 语句条件声明它应该只要求 5 个名称和 5 个余额，对吗？我在这里错过了什么吗？

UPDATE2：我已经解决了上述问题并改进了我的程序，现在我需要一些帮助来使用 API 中的applyPercentageIncrease方法Customer.class。我知道我在下面编写的代码不起作用，但如果使用上述方法将所有账户余额增加 5%，我将不胜感激。谢谢

    for (int e=0;e<5;e++)
{
  //Customer c = new Customer amount[e].applyPercentageIncrease(5);
  //amount [e]=
  //applyPercentageIncrease q = new 
  customers[o]=e.applyPercentageIncrease(5);
  System.out.println (o.getName()+" has "+o.getBalance());

}

标签： javaarraysclassobjectmethods

解决方案

您还应该声明 Customer 对象的数组（或者可能是 ArrayList 或 LinkedList）：

Customer[] customers = new Customer[5];

这样在 for 循环中你可以说：

for (int i=1;i<=5;i++)
{
  System.out.println("please enter the name of the customer");
  name[i] = input.next();
  System.out.println("please enter the amount in that account");
  amount[i] = input.nextDouble();

  customers[i] = new Customer(name[i],amount[i]); //set the i. element of the Customer array
}

现在您可以在此循环之后引用创建的 Customer 对象！

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