C# String Comparison? [duplicate]
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Using == or Equals for string comparison 开发者_开发技巧 Are string.Equals() and == operator really same?
I learned Java first and one of the few absolutes is that you never use == to compare if two strings are equal, instead there's the equals method. So when I landed in C# years ago and noticed that objects still had an Equals method, I assumed the rule still applied.
Now I'm going through an ex-coworker's code and I'm finding snippets like this everywhere:
if (s.Substring(0, s.IndexOf("_")) == "GBCI") {...}
If I recall correctly, == will compare the address between those two results and since the first half is returned by a function, this will fail because the result won't be the same address as the constant on the right.
Am I holding on to old Java habits? Or is it a good thing that my coworker isn't around any more?
P.S. Regardless your answer to comparing strings, I do realize the above would be better stated as s.BeginsWith("GBCI")
, but that's something else entirely.
In C#, ==
comparison for strings compares their values instead of their references. See this section of the C# spec for details.
So using it like that works fine; your coworker was sane and sober.
As another note, look at this link.
You can use ==
however compareTo
is unique in that it will return an integer based on how the strings differ (or don't differ).
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