Databases
StackOverflow2013
Postsdbo
PODoubts regarding Enum Strategy approach
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PODoubts regarding Enum Strategy approach
    primarykey
    data
    text
    <p>For computing Income Tax, I tried to use Enum Strategy approach to make the logic more concise. But in the end I’m not satisfied mainly because I had to write different enums for income groups, limits and rates. This was because they are all constants of different nature. But due to this the code doesn’t looks compact and seems to lack encapsulation.</p> <p><strong>Is my worry genuine? Please let me know your views or a better approach.</strong></p> <p>Say, Income Tax groups and corresponding rates are as follows:</p> <ul> <li>Income between 0 – 500000 : 10% taxable </li> <li>Income between 500001 – 1000000 : 20% taxable </li> <li>Income between 1000001 – Infinite : 30% taxable</li> </ul> <p>For example, Income Tax applicable on an income of 1200000 would be 30 % of 200000 (1200000 – 1000000) + 20% of 500000 (1000000 – 500000) + 10% of 500000 (500000 – 0) = 160000</p> <p><strong>Code</strong>:</p> <pre><code>package itcalc; public class IncomeTaxCalculatorImpl { private enum IncomeGroup { ONE(Limit.GROUP_ONE_LIMIT) { @Override public double calculate(double income) { return income * Rate.GROUP_ONE_RATE.value / 100; } }, TWO(Limit.GROUP_TWO_LIMIT) { @Override public double calculate(double income) { return ((income - Limit.GROUP_ONE_LIMIT.maximum) * Rate.GROUP_TWO_RATE.value / 100) + ONE.calculate(Limit.GROUP_ONE_LIMIT.maximum); } }, THREE(Limit.GROUP_THREE_LIMIT) { @Override public double calculate(double income) { return ((income - Limit.GROUP_TWO_LIMIT.maximum) * Rate.GROUP_THREE_RATE.value / 100) + TWO.calculate(Limit.GROUP_TWO_LIMIT.maximum - Limit.GROUP_ONE_LIMIT.maximum) + ONE.calculate(Limit.GROUP_ONE_LIMIT.maximum); } }; private final Limit limit; private enum Limit { GROUP_ONE_LIMIT(0, 500000), GROUP_TWO_LIMIT(500001, 1000000), GROUP_THREE_LIMIT(1000001, Double.MAX_VALUE); private final double minimum; private final double maximum; private Limit(double minimum, double maximum) { this.minimum = minimum; this.maximum = maximum; } } private enum Rate { GROUP_ONE_RATE(10), GROUP_TWO_RATE(20), GROUP_THREE_RATE(30); private final double value; private Rate(double value) { this.value = value; } } private IncomeGroup(Limit limit) { this.limit = limit; } abstract double calculate(double income); } public double calculate(double income) { for (IncomeGroup group : IncomeGroup.values()) { if (income &gt;= group.limit.minimum &amp;&amp; income &lt;= group.limit.maximum) { return group.calculate(income); } } throw new IllegalArgumentException("Invalid Income Value"); } } </code></pre>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USMark
    1. UShaps10
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. PODoubts regarding Enum Strategy approach
      1. This table or related slice is empty.
      1. VTUpMod
    1. COReformatted code; please revert if incorrect.
      singulars
      1. PODoubts regarding Enum Strategy approach
      1. UStrashgod
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload