这是一个嵌套的 if 吗？和while循环？不确定我是否正确使用它们。但我遇到了错误。 “否则没有如果”

Question

//决定用户是否会在支付的基础上获得佣金。

import java.util.Scanner;
public class commiPay{
    public static void main( String[] args ){
        Scanner input = new Scanner(System.in);
        int pay = 200;
        double com;
        double sales;
        double x;
        while ( sales = -1 )// I want the user to enter positive numbers
        {
            System.out.printf( "Sales cannot be negative");
            System.out.printf( "Enter sales sold this week: ");
        }
        System.out.println("Enter sales made this week: ");
        sales = input.nextInt(); 
        if ( sales >= 7500 )/*got this format from the traditional letter grade java example**/
        {
            System.out.println( "Commission is multiplied by 5%. " );
            com = sales*.5;
         else if ( sales >= 5001 )
             System.out.println( "Commission is multiplied by 4%. " );
             com = sales*.4;
         else if ( sales >= 2501 )
             System.out.println( "Commission is multiplied by 3%. " );
            com = sales*.3;   
         else if ( sales >= 1001 )
             System.out.println( "Commission is multiplied by 2%. " );
             com = sales*.2;    
         else ( sales < 1000 )
             System.out.println( "No commission. " );
             total = pay;
         }
         System.out.println( "You will get paid" + total + "this week."  );
     }
}

销售人员的报酬是每周 200.00 美元，外加 佣金。佣金取决于她（他）在一周内的销售额。

编写一个程序，提示用户一周的销售额（销售额使用整数）。

如果输入的金额小于 0，则显示一条错误消息，告诉用户“销售额不能为负数！”

使用下表中的信息，确定销售人员的佣金应该是多少。佣金应基于当周的总销售额。

佣金表：

        up to 1,000                              no commission
        1,001 – 2,500                            2% of sales
        2,501 – 5,000                            3% of sales
        5,001 – 7,500                            4% of sales
        over 7,500                               5% of sales

Answer 1

确保正确格式化 if/elseif/else 语句：

if() {

} else if() {

} else if() {

} else {

}

Answer 2

如果你的 else if 后面有不止一行，你需要把它放在大括号内，以确保你的程序不会混淆。据我所知，您只能使用

else if(something)
     indented something;
else if(something else)
etc.

如果你只有一行。

else if ( sales >= 5001 )
             System.out.println( "Commission is multiplied by 4%. " );
             com = sales*.4;

需要

else if ( sales >= 5001 ){
             System.out.println( "Commission is multiplied by 4%. " );
             com = sales*.4;
}

等等。

Answer 3

您的代码缺少括号，并且在您的while condition 中，并且计算也是错误的。

import java.util.Scanner;
public class commiPay{
public static void main( String[] args ){
Scanner input = new Scanner(System.in);
    int pay = 200;
    double com;
    double sales = 0;
    double x;
    double total; // added this variable

    //First you need to get the user input. So I added these two lines to here.
    System.out.println("Enter sales made this week: ");
    sales = input.nextInt();

    //Checking whether enterd number is a positive or not
    while ( sales < 0 )// I want the user to enter positive numbers
    {
        System.out.printf( "Sales cannot be negative ");
        System.out.printf( "Enter sales sold this week: ");
        sales = input.nextInt(); // if the entered number is an negative number ask the user to re enter the number 
    }

    if ( sales >= 7500 )/*got this format from the traditional letter grade java example**/
    {
        System.out.println( "Commission is multiplied by 5%. " );
        com = sales*0.05;
    }
     else if ( sales >= 5001 ){
         System.out.println( "Commission is multiplied by 4%. " );
         com = sales*0.04;
     }
     else if ( sales >= 2501 ){
         System.out.println( "Commission is multiplied by 3%. " );
        com = sales*0.03;
     }
     else if ( sales >= 1001 ){
         System.out.println( "Commission is multiplied by 2%. " );
         com = sales*0.02;
     }
     else if( sales < 1000 ){
         System.out.println( "No commission. " );
         total = pay;
     }
}
}

Answer 4

您的代码中缺少很多括号。您还需要初始化变量。输入小于 1000 的值，您将看到代码现在可以工作。还有一些我修复的尚未实现的代码。在每个 if 或 else if 块中，您需要将 com 和 pay 变量添加到您的 total 变量中。我还注意到您的佣金公式中的小数点已取消。

例如：

您的代码中有这个com = sales * .2;，这将产生 20% 的佣金，而不是代码 cmets 中的 2%。正确的公式是：

com = sales * 0.02;

我在你的代码中应用了这个修复。

    /decides if user will get commission on top of pay.

import java.util.Scanner;

public class commiPay {

public static void main( String[] args )

{ 

    Scanner input = new Scanner(System.in);




  double pay = 200;

  //added this variable(was missing from your code)
  double total = 0;

  double com = 0;//

  //intialize sales variable
  double sales = 0;

  double x;


  //The following to lines were moved to before the while loop
  System.out.println("Enter sales made this week: ");

     sales = input.nextInt();


  //while the sales number is positive
 while ( sales < 0 )// I want the user to enter positive numbers
  {
     System.out.printf( "Sales cannot be negative");


     System.out.println("Enter sales made this week: ");

         sales = input.nextInt();
  }









  if ( sales >= 7500 )/*got this format from the traditional letter grade java example**/
   {
     System.out.println( "Commission is multiplied by 5%. " );

       com = sales * 0.05;

     //add the commission to the total
       total = pay + com;

   }





 else if ( sales >= 5001 ){//added bracket

     System.out.println( "Commission is multiplied by 4%. " );
     com = sales * 0.04;

     //add the commission to the total
     total = pay + com;

 }//added bracket//added bracket//added bracket//added bracket
  else if ( sales >= 2501 ){//added bracket


     System.out.println( "Commission is multiplied by 3%. " );

      com = sales * 0.03;

    //add the commission to the total
       total = pay + com;

  }//added bracket//added bracket//added bracket//added bracket
  else if ( sales >= 1001 ){//added brace

      System.out.println( "Commission is multiplied by 2%. " );

       com = sales * 0.02;

       //add the commission to the total
       total = pay + com;


  }//added bracket//added bracket//added bracket//added bracket
  else if( sales < 1000 ){


     System.out.println( "No commission. " );
             total = pay;

   }




  System.out.println( "You will get paid " + (total) + " this week."  );





   }//end main method

}//end class

Answer 5

你有以下：

    while ( sales = -1)

但如果他们没有专门输入 -1 怎么办？应该是：

    while ( sales < 0 )

这将涵盖所有负数。您还应该修改括号，因为您似乎缺少一些。您也可以在 while 循环之后不使用 printf 并使用标准 println：

    while ( sales = -1 )// I want the user to enter positive numbers
    {
        System.out.printf( "Sales cannot be negative");
        System.out.printf( "Enter sales sold this week: ");

但我认为这不会造成问题。

至于代码的其余部分，您在打印的行中声明销售额将乘以 5%，但将它们乘以 0.5（如下所示）：

    System.out.println( "Commission is multiplied by 5%. " );
        com = sales*.5;

乘以 0.5 等于 50%。尝试将其换成 0.05 (5/100)。