C＃String：为什么字符串a == b运算符给出的答案不同于a.CompareTo（b）== 0？

Question

I messed with C# a little and found a code that gives very uncomfortable results:

static void Main(string[] args)
    {
        string a = "string", b = "string\0";
        bool b1 = a == b;
        bool b2 = (a.CompareTo(b) > 0);
        bool b3 = (a.CompareTo(b) < 0);
        bool b4 = (a.CompareTo(b) == 0);
        Console.WriteLine(a);
        Console.WriteLine(b);
        Console.WriteLine("{0} {1} {2} {3}", b1, b2, b3, b4);
    }

Output:

string
string
False False False True

Expected output (on of the):

string
string
True False False True

Answer 1

The result of CompareTo doesn't imply equality, it relates to sort order. I'm not sure it's too surprising that the null character is ignored for sorting purposes.

Per the documentation :

Character sets include ignorable characters. The CompareTo(String) method does not consider such characters when it performs a culture-sensitive comparison.

Answer 2

You want StringComparison.Ordinal flag: just compare strings lexicographically:

...
bool b2 = (a.CompareTo(b, StringComparison.Ordinal) > 0);
bool b3 = (a.CompareTo(b, StringComparison.Ordinal) < 0);
bool b4 = (a.CompareTo(b, StringComparison.Ordinal) == 0);
...

Answer 3

String.CompareTo returns 0 if the string instance has the same position in the sort order as the supplied value. This is something different than comparing for equality. So I would expect the outcome as you describe.