- Strings and Nulls in C#<DIV>A very common thing in coding is to want to see if you've been given a string or not.</DIV>
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<DIV>In C#, a string is a reference to an object, and this reference can be null, or it can be a reference to a string, which can contain 0 or more characters.</DIV>
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<DIV>When you want to see if you have a string or not, you need to first check to see if it's a null reference, and if it's not, then see if the string contains any characters. This ends up looking something like:</DIV>
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<DIV> if (firstName != null && firstName.Length > 0)</DIV>
<DIV> {</DIV>
<DIV> // do something with firstName </DIV>
<DIV> }</DIV>
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<DIV>If I'm calling a function that doesn't require a first name, I can pass in a null. The disconnect is that if I'm, say, reading data from a text file and the file has a place where the name is going to be, the empty case for the string is simply going to be a string with no characters.</DIV>
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<DIV>So someone has to say 'this string with no characters is really a null', or everywhere you access the string, you need to see if it's null.</DIV>
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<DIV>I don't have any great insight to offer here; I just find it less than elegant. I'd like a way to test to see if a string is both non-null and non-empty without having to do the two separate comparisons.</DIV>
<DIV> </DIV>Thu, 01 Sep 2005 19:17:07 GMT