CODEWITHSUNDEEP
c#stringcase-insensitive
divinci
divinci

Reputation: 23169

C# Case-Insensitive String

Considering the class below
- can I do anything to implement a case-insensitive string?

public class Attibute
{
    // The Name should be case-insensitive
    public string Name
    {
        get;
        set;
    }

    public Attibute()
    {
    }
}

public class ClassWithAttributes
{
    private List<Attributes> _attributes;

    public ClassWithAttributes(){}

    public AddAttribute(Attribute attribute)
    {
        // Whats the best way to implement the check?
        _attributes.add(attribute);
    }
}

Structure of an HTML 4 Document

I have edited the class to be a bit more objective and specific

Upvotes: 0

Views: 4384

Answers (5)

SLaks
SLaks

Reputation: 888177

In answer to the restructured question, you could do it like this:

public class Attribute { public string Name { get; set; } }

public class AttributeCollection : KeyedCollection<string, Attribute> {
    public AttributeCollection() : base(StringComparer.OrdinalIgnoreCase) { }
    protected override string GetKeyForItem(Attribute item) { return item.Name; }
}

public class ClassWithAttributes {
    private AttributeCollection _attributes;

    public void AddAttribute(Attribute attribute) {
        _attributes.Add(attribute);    
        //KeyedCollection will throw an exception
        //if there is already an attribute with 
        //the same (case insensitive) name.
    }
}

If you use this, you should either make Attribute.Name read-only or call ChangeKeyForItem whenever it's changed.

Upvotes: 2

SLaks
SLaks

Reputation: 888177

Alternatively, you might want to make the property always uppercase, like this.

public class XHtmlOneDTDElementAttibute : ElementRegion {
    string name;

    // The Name should be case-insensitive
    public string Name {
        get { return name; }
        set { name = value.ToUpperInvariant(); }
    }

    // The Value should be case-sensitive
    public string Value { get; set; }
}

Upvotes: 1

Michael Petrotta
Michael Petrotta

Reputation: 60972

Well, my take on this, after glancing at the spec, is that there's nothing you need to do to make the string properties case-insensitive. The concept doesn't really make sense, anyway: strings aren't case-sensitive or -insensitive; operations on them (like search and sort) are.

(I know the W3C's HTML recommendations say essentially that. It's badly-phrased.)

Upvotes: 1

SLaks
SLaks

Reputation: 888177

It depends what you're trying to do with the strings.

If you want to compare strings regardless of case, call String.Equals with StringComparison.OrdinalIgnoreCase. If you want to put them in a dictionary, make the dictionary's comparer StringComparer.OrdinalIgnoreCase.

Therefore, you could make a function as follows:

public class XHtmlOneDTDElementAttibute : ElementRegion {
    public bool IsTag(string tag) {
        return Name.Equals(tag, StringComparison.OrdinalIgnoreCase);
    }

    // The Name should be case-insensitive
    public string Name { get; set; }

    // The Value should be case-sensitive
    public string Value { get; set; }
}

If you want a more specific solution, please tell me what you're doing with the Name property

Upvotes: 1

Dave Bauman
Dave Bauman

Reputation: 9708

You can't have case-insensitive properties—you can only have case-insensitive operations, like a comparison. If someone accesses XHtmlOneDTDElementAttibute.Name, they will get back a string with whatever case it was created with.

Whenever you use .Name, you can implement that method in a way that ignores the case of the string.

Upvotes: 2

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