如何将大量条件压缩到查找数组中？

Question

我正在尝试编写一个函数来查找汽车保险支付的 $InterestRate 值。我在代码下面插入了table：

目前我尝试过：

function interestRate() {
if ((int)$VehicleYear >= 2001) && (int)$VehicleYear <= 2005){

    $Term = 24;

    if ((int)$CreditScore >= 720){
        $InterestRate = 15.90;
    }
    elseif ((int)$CreditScore >= 610) || ((int)$CreditScore <= 719) {
        $InterestRate = 19.90;
    }
    elseif ((int)$CreditScore >= 580) || ((int)$CreditScore <= 609) {
        $InterestRate = 22.90;
    }
    elseif ((int)$CreditScore >= 530) || ((int)$CreditScore <= 579) {
        $InterestRate = 22.90;
    }
    elseif ((int)$CreditScore >= 489) || ((int)$CreditScore <= 529) {
        $InterestRate = 22.90;
    }
}

if ((int)$VehicleYear == 2006){

    $Term = 24;

    if ((int)$CreditScore >= 720){
        $InterestRate = 15.90;
    }
    elseif ((int)$CreditScore >= 610) || ((int)$CreditScore <= 719) {
        $InterestRate = 18.90;
    }
    elseif ((int)$CreditScore >= 580) || ((int)$CreditScore <= 609) {
        $InterestRate = 21.90;
    }
    elseif ((int)$CreditScore >= 530) || ((int)$CreditScore <= 579) {
        $InterestRate = 22.90;
    }
    elseif ((int)$CreditScore >= 489) || ((int)$CreditScore <= 529) {
        $InterestRate = 22.90;
    }
}
if ((int)$VehicleYear == 2007){

    $Term = 36;

    if ((int)$CreditScore >= 720){
        $InterestRate = 15.90;
    }
    elseif ((int)$CreditScore >= 610) || ((int)$CreditScore <= 719) {
        $InterestRate = 18.90;
    }
    elseif ((int)$CreditScore >= 580) || ((int)$CreditScore <= 609) {
        $InterestRate = 21.90;
    }
    elseif ((int)$CreditScore >= 530) || ((int)$CreditScore <= 579) {
        $InterestRate = 22.90;
    }
    elseif ((int)$CreditScore >= 489) || ((int)$CreditScore <= 529) {
        $InterestRate = 22.90;
    }
}
if ((int)$VehicleYear == 2008){

    $Term = 36;

    if ((int)$CreditScore >= 720){
        $InterestRate = 14.90;
    }
    elseif ((int)$CreditScore >= 610) || ((int)$CreditScore <= 719) {
        $InterestRate = 17.90;
    }
    elseif ((int)$CreditScore >= 580) || ((int)$CreditScore <= 609) {
        $InterestRate = 21.90;
    }
    elseif ((int)$CreditScore >= 530) || ((int)$CreditScore <= 579) {
        $InterestRate = 21.90;
    }
    elseif ((int)$CreditScore >= 489) || ((int)$CreditScore <= 529) {
        $InterestRate = 21.90;
    }
}

if ((int)$VehicleYear == 2009){

    $Term = 36;

    if ((int)$CreditScore >= 720){
        $InterestRate = 14.90;
    }
    elseif ((int)$CreditScore >= 610) || ((int)$CreditScore <= 719) {
        $InterestRate = 17.90;
    }
    elseif ((int)$CreditScore >= 580) || ((int)$CreditScore <= 609) {
        $InterestRate = 20.90;
    }
    elseif ((int)$CreditScore >= 530) || ((int)$CreditScore <= 579) {
        $InterestRate = 20.90;
    }
    elseif ((int)$CreditScore >= 489) || ((int)$CreditScore <= 529) {
        $InterestRate = 20.90;
    }
}

if ((int)$VehicleYear == 2010){

    $Term = 36;

    if ((int)$CreditScore >= 720){
        $InterestRate = 14.90;
    }
    elseif ((int)$CreditScore >= 610) || ((int)$CreditScore <= 719) {
        $InterestRate = 17.90;
    }
    elseif ((int)$CreditScore >= 580) || ((int)$CreditScore <= 609) {
        $InterestRate = 20.90;
    }
    elseif ((int)$CreditScore >= 530) || ((int)$CreditScore <= 579) {
        $InterestRate = 20.90;
    }
    elseif ((int)$CreditScore >= 489) || ((int)$CreditScore <= 529) {
        $InterestRate = 20.90;
    }
}

if ((int)$VehicleYear == 2011){

    $Term = 42;

    if ((int)$CreditScore >= 720){
        $InterestRate = 14.90;
    }
    elseif ((int)$CreditScore >= 610) || ((int)$CreditScore <= 719) {
        $InterestRate = 16.90;
    }
    elseif ((int)$CreditScore >= 580) || ((int)$CreditScore <= 609) {
        $InterestRate = 19.90;
    }
    elseif ((int)$CreditScore >= 530) || ((int)$CreditScore <= 579) {
        $InterestRate = 19.90;
    }
    elseif ((int)$CreditScore >= 489) || ((int)$CreditScore <= 529) {
        $InterestRate = 20.90;
    }
}

if ((int)$VehicleYear == 2012){

    $Term = 42;

    if ((int)$CreditScore >= 720){
        $InterestRate = 12.90;
    }
    elseif ((int)$CreditScore >= 610) || ((int)$CreditScore <= 719) {
        $InterestRate = 15.90;
    }
    elseif ((int)$CreditScore >= 580) || ((int)$CreditScore <= 609) {
        $InterestRate = 18.90;
    }
    elseif ((int)$CreditScore >= 530) || ((int)$CreditScore <= 579) {
        $InterestRate = 19.90;
    }
    elseif ((int)$CreditScore >= 489) || ((int)$CreditScore <= 529) {
        $InterestRate = 19.90;
    }
}

if ((int)$VehicleYear == 2013){

    $Term = 42;

    if ((int)$CreditScore >= 720){
        $InterestRate = 12.90;
    }
    elseif ((int)$CreditScore >= 610) || ((int)$CreditScore <= 719) {
        $InterestRate = 15.90;
    }
    elseif ((int)$CreditScore >= 580) || ((int)$CreditScore <= 609) {
        $InterestRate = 18.90;
    }
    elseif ((int)$CreditScore >= 530) || ((int)$CreditScore <= 579) {
        $InterestRate = 18.90;
    }
    elseif ((int)$CreditScore >= 489) || ((int)$CreditScore <= 529) {
        $InterestRate = 18.90;
    }
}

if ((int)$VehicleYear >= 2014){

    $Term = 48;

    if ((int)$CreditScore >= 720){
        $InterestRate = 11.90;
    }
    elseif ((int)$CreditScore >= 610) || ((int)$CreditScore <= 719) {
        $InterestRate = 14.90;
    }
    elseif ((int)$CreditScore >= 580) || ((int)$CreditScore <= 609) {
        $InterestRate = 17.90;
    }
    elseif ((int)$CreditScore >= 530) || ((int)$CreditScore <= 579) {
        $InterestRate = 18.90;
    }
    elseif ((int)$CreditScore >= 489) || ((int)$CreditScore <= 529) {
        $InterestRate = 18.90;
    }
}
}

当我尝试在计算中使用 $InterestRate 时，它既乏味又根本不起作用。解决这个问题的最佳方法是什么？

EDIT ：有些人提到使用 SQL table。我不知道该怎么做。但这是我的 table 基本上

<table style="undefined;table-layout: fixed; width: 497px">
<colgroup>
<col style="width: 93px">
<col style="width: 73px">
<col style="width: 75px">
<col style="width: 64px">
<col style="width: 64px">
<col style="width: 64px">
<col style="width: 64px">
</colgroup>
  <tr>
    <th>Vehicle Year</th>
    <th>Term</th>
    <th>FICO</th>
    <th>FICO</th>
    <th>FICO</th>
    <th>FICO</th>
    <th>FICO</th>
  </tr>
  <tr>
    <td></td>
    <td></td>
    <td>720 +</td>
    <td>719-610</td>
    <td>609-580</td>
    <td>579-530</td>
    <td>529-489</td>
  </tr>
  <tr>
    <td>2014-current</td>
    <td>48</td>
    <td>11</td>
    <td>14</td>
    <td>17</td>
    <td>18</td>
    <td>18</td>
  </tr>
  <tr>
    <td>2013</td>
    <td>42</td>
    <td>12</td>
    <td>15</td>
    <td>18</td>
    <td>18</td>
    <td>18</td>
  </tr>
  <tr>
    <td>2012</td>
    <td>42</td>
    <td>12</td>
    <td>15</td>
    <td>18</td>
    <td>19</td>
    <td>19</td>
  </tr>
  <tr>
    <td>2011</td>
    <td>42</td>
    <td>14</td>
    <td>16</td>
    <td>19</td>
    <td>19</td>
    <td>20</td>
  </tr>
  <tr>
    <td>2010</td>
    <td>36</td>
    <td>14</td>
    <td>17</td>
    <td>20</td>
    <td>20</td>
    <td>20</td>
  </tr>
  <tr>
    <td>2009</td>
    <td>36</td>
    <td>14</td>
    <td>17</td>
    <td>20</td>
    <td>20</td>
    <td>20</td>
  </tr>
  <tr>
    <td>2008</td>
    <td>36</td>
    <td>14</td>
    <td>17</td>
    <td>21</td>
    <td>21</td>
    <td>21</td>
  </tr>
  <tr>
    <td>2007</td>
    <td>36</td>
    <td>15</td>
    <td>18</td>
    <td>21</td>
    <td>22</td>
    <td>21</td>
  </tr>
  <tr>
    <td>2006</td>
    <td>24</td>
    <td>15</td>
    <td>18</td>
    <td>21</td>
    <td>22</td>
    <td>22</td>
  </tr>
  <tr>
    <td>2001-2005</td>
    <td>24</td>
    <td>15</td>
    <td>19</td>
    <td>22</td>
    <td>22</td>
    <td>22</td>
  </tr>
</table>
Extra o

Answer 1

给你：删除所有重复代码：

function creditScore( $cs ) {
    $cs = (int) $cs;

    if     ($cs >= 720)               return 5;
    elseif ($cs >= 610 && $cs <= 719) return 4;
    elseif ($cs >= 580 && $cs <= 609) return 3;
    elseif ($cs >= 530 && $cs <= 579) return 2;
    elseif ($cs >= 489 && $cs <= 529) return 1;
    else                              return 0;
}

function interestRate($vehicleYear, $creditScore) {
    $vehicleYear = (int) $vehicleYear;
    $cred = creditScore( $creditScore );
    if ( ! $cred )      // handle credit score below 489: returns 0
        throw new Exception("Unsupported creditScore: $creditScore" );
    $cred--;    // otherwise it's 1..5, change to 0..4 for array index

    $rates = [
        2001 => [ 'term' => 24, 'rates' => [ 22.90, 22.90, 22.90, 19.90, 15.90 ] ],
        2002 => [ 'term' => 24, 'rates' => [ 22.90, 22.90, 22.90, 19.90, 15.90 ] ],
        2003 => [ 'term' => 24, 'rates' => [ 22.90, 22.90, 22.90, 19.90, 15.90 ] ],
        2004 => [ 'term' => 24, 'rates' => [ 22.90, 22.90, 22.90, 19.90, 15.90 ] ],
        2005 => [ 'term' => 24, 'rates' => [ 22.90, 22.90, 22.90, 19.90, 15.90 ] ],
        2006 => [ 'term' => 24, 'rates' => [ 22.90, 22.90, 21.90, 18.90, 15.90 ] ],
        2007 => [ 'term' => 36, 'rates' => [ 22.90, 22.90, 21.90, 18.90, 15.90 ] ],
        2008 => [ 'term' => 36, 'rates' => [ 22.90, 22.90, 21.90, 17.90, 14.90 ] ],
        2009 => [ 'term' => 36, 'rates' => [ 20.90, 20.90, 20.90, 17.90, 14.90 ] ],
        2010 => [ 'term' => 36, 'rates' => [ 20.90, 20.90, 20.90, 17.90, 14.90 ] ],
        2011 => [ 'term' => 42, 'rates' => [ 20.90, 19.90, 19.90, 16.90, 14.90 ] ],
        2012 => [ 'term' => 42, 'rates' => [ 19.90, 19.90, 18.90, 15.90, 12.90 ] ],
        2013 => [ 'term' => 42, 'rates' => [ 18.90, 18.90, 18.90, 15.90, 12.90 ] ],
        2014 => [ 'term' => 48, 'rates' => [ 18.90, 18.90, 17.90, 14.90, 11.90 ] ],
    ];

    return [ // TODO: check if isset( $rates[$vehicleYear ])
        $rates[$vehicleYear]['rates'][ $cred ],
        $rates[$vehicleYear]['term']
    ];
}

list( $interestRate, $term ) = interestRate( 2013, 666 );

Answer 2

我喜欢 Kenney 的一些回答，但不是全部。 I lookup array for rates 是个好主意，但它应该只声明一次而不是每次调用函数时。 ifs的short battery确定信用评分指标是好的，但是每个分支的第二个条件（<=）在逻辑上是不必要的。

我建议将查找数组定义为常量，以便它只声明一次并具有全局范围。这是完全合适的，因为查找中的金额 table 在处理过程中不应更改。

当查找数组设计得当时，maintenance/extension应该只涉及调整查找数组而不是处理代码。

这会将您的 php 代码设置为离传输到数据库仅一步之遥 table -- 如果您的应用程序发现对数据维护或扩展的需求增加。

代码：(Demo)

define(
    'TERM_RATES_BY_YEAR',
    [
        2001 => ['term' => 24, 'rates' => [15.90, 19.90, 22.90, 22.90, 22.90]],
        2002 => ['term' => 24, 'rates' => [15.90, 19.90, 22.90, 22.90, 22.90]],
        2003 => ['term' => 24, 'rates' => [15.90, 19.90, 22.90, 22.90, 22.90]],
        2004 => ['term' => 24, 'rates' => [15.90, 19.90, 22.90, 22.90, 22.90]],
        2005 => ['term' => 24, 'rates' => [15.90, 19.90, 22.90, 22.90, 22.90]],
        2006 => ['term' => 24, 'rates' => [15.90, 18.90, 21.90, 22.90, 22.90]],
        2007 => ['term' => 36, 'rates' => [15.90, 18.90, 21.90, 22.90, 22.90]],
        2008 => ['term' => 36, 'rates' => [14.90, 17.90, 21.90, 22.90, 22.90]],
        2009 => ['term' => 36, 'rates' => [14.90, 17.90, 20.90, 20.90, 20.90]],
        2010 => ['term' => 36, 'rates' => [14.90, 17.90, 20.90, 20.90, 20.90]],
        2011 => ['term' => 42, 'rates' => [14.90, 16.90, 19.90, 19.90, 20.90]],
        2012 => ['term' => 42, 'rates' => [12.90, 15.90, 18.90, 19.90, 19.90]],
        2013 => ['term' => 42, 'rates' => [12.90, 15.90, 18.90, 18.90, 18.90]],
        2014 => ['term' => 48, 'rates' => [11.90, 14.90, 17.90, 18.90, 18.90]],
    ]
);
define('CREDIT_SCORE_MINIMUM_THRESHOLDS', [720, 610, 580, 530, 489]);

/** @throws Exception */
function getRateIndexFromCreditScore(int $creditScore): ?int
{
    foreach (CREDIT_SCORE_MINIMUM_THRESHOLDS as $rateIndex => $minThreshold) {
        if ($creditScore >= $minThreshold) {
            return $rateIndex;
        }
    }
    throw new Exception("Sorry, your credit score ($creditScore) does not qualify for financing");
}

foreach (range(2000, 2015) as $year) {
    try {
        if (!isset(TERM_RATES_BY_YEAR[$year])) {
            throw new Exception("Sorry, your vehicle year ($year) does not qualify for financing");
        }
        $score = rand(300, 850);
        $rateIndex = getRateIndexFromCreditScore($score);
        $outcome = sprintf(
            'Vehicle Year: %d, Credit Score: %d, Term: %d, Rate: %.2f',
            $year,
            $score,
            TERM_RATES_BY_YEAR[$year]['term'],
            TERM_RATES_BY_YEAR[$year]['rates'][$rateIndex]
        );
    } catch (Exception $e) {
        $outcome = $e->getMessage();
    }
    echo "$outcome\n";
}

潜在产出：

Sorry, your vehicle year (2000) does not qualify for financing
Vehicle Year: 2001, Credit Score: 758, Term: 24, Rate: 15.90
Sorry, your credit score (401) does not qualify for financing
Vehicle Year: 2003, Credit Score: 751, Term: 24, Rate: 15.90
Vehicle Year: 2004, Credit Score: 545, Term: 24, Rate: 22.90
Sorry, your credit score (481) does not qualify for financing
Vehicle Year: 2006, Credit Score: 658, Term: 24, Rate: 18.90
Vehicle Year: 2007, Credit Score: 745, Term: 36, Rate: 15.90
Vehicle Year: 2008, Credit Score: 836, Term: 36, Rate: 14.90
Vehicle Year: 2009, Credit Score: 803, Term: 36, Rate: 14.90
Sorry, your credit score (466) does not qualify for financing
Vehicle Year: 2011, Credit Score: 792, Term: 42, Rate: 14.90
Vehicle Year: 2012, Credit Score: 763, Term: 42, Rate: 12.90
Vehicle Year: 2013, Credit Score: 534, Term: 42, Rate: 18.90
Vehicle Year: 2014, Credit Score: 493, Term: 48, Rate: 18.90
Sorry, your vehicle year (2015) does not qualify for financing

如何将大量条件压缩到查找数组中？

How to condense a large battery of conditions into a lookup array?

php

refactoring

function

lookup-tables