a couple of questions about System.String

This is a discussion on a couple of questions about System.String within the C# Programming forums, part of the General Programming Boards category; System.String lacks a couple of things that I would have thought would be standard behavior. First, it has no member ...

  1. #1
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    a couple of questions about System.String

    System.String lacks a couple of things that I would have thought would be standard behavior. First, it has no member to tell you if the string is empty. the only way is to write the code

    Code:
    if (myString.length == 0)
    The C++ std::string has this functionality, and I use it all the time.

    Second, I cannot derive a class from System.String to add this functionality. Why would microsoft make it a sealed class, when it's reasonable to expect that someone might want to inherit the functionality of a string?

  2. #2
    a_capitalist_story
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    .NET 2.0 has the static member String.IsNullOrEmpty(myString).

  3. #3
    Confused Magos's Avatar
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    In recent versions of dot net (3.0+ ?) there are extension methods. Technically they are static functions but act as if they were methods. LINQ makes good use of these.

    If you want the method approach you could write one like this (note the "this" in the argument list):

    Code:
    namespace StringExtensions
    {
    	public static class StringExtensions
    	{
    		public static bool IsEmpty(this string String)
    		{
    			return string.IsNullOrEmpty(String);
    		}
    	}
    }
    And then be able to use it like this:

    Code:
    using StringExtensions;
    
    var MyString = "Hello";
    MyString.IsEmpty();
    The namespace must be opened manually ("using") or the extension methods cannot be found.
    MagosX.com

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  4. #4
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    Unfortunately, I do not know where or when this was introduced, but it has a member called Empty.

    Code:
    if(someString == string.Empty)
        // .. etc ..
    "What's up, Doc?"
    "'Up' is a relative concept. It has no intrinsic value."

  5. #5
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    Quote Originally Posted by IceDane View Post
    Unfortunately, I do not know where or when this was introduced, but it has a member called Empty.

    Code:
    if(someString == string.Empty)
        // .. etc ..
    I noticed that too, but it's not quite what i was looking for. I studied up on extension methods, and that got me exactly what I needed.

    Thanks everyone.

  6. #6
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    Quote Originally Posted by Elkvis View Post
    I noticed that too, but it's not quite what i was looking for. I studied up on extension methods, and that got me exactly what I needed.

    Thanks everyone.
    Extension methods are really awesome indeed, but keep in mind that they are a relatively new addition to the framework. They were only added as late as C# 3.0.
    "What's up, Doc?"
    "'Up' is a relative concept. It has no intrinsic value."

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