How do I reduce the "Cyclomatic Complexity" of the following code

Question

I am wondering how to reduce the Cyclomatic Complexity of the following code and if this is even something that I should be worried about.

Please refer to the method ValuePojo.getSomething() (Please don't worry about the variable naming, this has been re-written for clarity in this question)

public class ValuePojo
{
    private ValueTypeEnum type;

    private BigDecimal    value1;

    private BigDecimal    value2;

    private BigDecimal    value3;

    public ValuePojo()
    {
        super();
    }

    /**
     * This method reports as "HIGH Cyclomatic Complexity"
     * 
     * @return
     */
    public BigDecimal getSomething()
    {
        if (this.type == null)
        {
            return null;
        }

        switch (this.type)
        {
            case TYPE_A:
            case TYPE_B:
            case TYPE_C:
            case TYPE_D:
                return this.value1;

            case TYPE_E:
            case TYPE_F:
            case TYPE_G:
            case TYPE_H:
                return this.value2;

            case TYPE_I:
            case TYPE_J:
                return this.value3;
        }

        return null;
    }
}

Answer 1

If you really need to get the cyclomatic complexity down, you can consider using a Map. Obviously, in your implementation, it should only be created and initialized once.

  public BigDecimal getSomething() {
      if (this.type == null) {
          return null;
      }
      Map<Type,BigDecimal> map = new HashMap<Type,BigDecimal>();
      map.put(TYPE_A, value1);
      map.put(TYPE_B, value1);
      map.put(TYPE_C, value1);
      map.put(TYPE_D, value1);
      map.put(TYPE_E, value2);
      map.put(TYPE_F, value2);
      map.put(TYPE_G, value2);
      map.put(TYPE_H, value2);
      map.put(TYPE_I, value3);
      map.put(TYPE_J, value3);

      return map.get(type);
  }

Answer 2

The Cyclomatic Complexity is determined by the number of branches of execution in your code. if - else blocks, switch statements - all increase the Cyclomatic complexity of your code and also increase the number of test cases you would need to ensure appropriate code coverage.

To reduce complexity in your code, I would suggest you remove the case statements that do not have a defined behavior and replace it with a default behavior in your switch statement.

Here is another question on Stack Overflows that addresses this issue.