检查枚举值 - 替代具有 30 个案例的开关案例？

Question

I need to find if all conditions fit a certain criteria.

public class OfferServiceConditionDto
{

    public long Id { get; set; }

    public Parameter Parameter { get; set; }

    public Enums.Condition Condition { get; set; }

    public double? Value { get; set; }

    [JsonIgnore]
    public long? OfferSubServiceId { get; set; }
}

Parameters has 5 cases:

 public enum Parameter: int { Length, Width Height, Area, Volume }

Condition has 6 cases:

public enum Condition : int
{
    LessThan,
    LessThanOrEqualTo,
    Equals,
    GreaterThan,
    GreaterThanOrEqualTo,
    DoesNotEqual
}

IN my function I am given an element width height and length and I need to check against OfferServiceConditionDto conditions, paremeters and value.

So far I am only thinking switch cases or ifs but that's a whooping 30 checks.

Any better alternative for this?

Answer 1

Just extract some methods. By doing so, you can easily turn 30 (5 * 6) cases into 11 (5 + 6).

public static bool CheckCondition(double width, double height, double length, OfferServiceConditionDto dto) {
    switch (dto.Parameter) {
    case Parameter.Length:
        return CheckCondition(dto.Condition, length, dto.Value);
    case Parameter.Height:
        return CheckCondition(dto.Condition, height, dto.Value);
    // plus 3 more...
    }
    return false;
}

private static bool CheckCondition(Enums.Condition condition, double value1, double? value2) {
    if (value2 == null) {
        return true; // decide what to do if Value is null
    }
    switch (condition) {
    case Enums.Condition.LessThan:
        return value1 < value2.Value;
    case Enums.Condition.LessThanOrEqualTo:
        return value1 <= value2.Value;
    // plus 4 more...
    }
    return false;
}