vb.net 在 c# 中为什么 (char)(1) + (char)(2) 结果为 int 3
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In c# why (char)(1) + (char)(2) results in int 3
提问by SarkarG
I am trying to covert some VB.NET code to C# and found this interesting thing. Adding two chars returns different results in VB.NET and C#.
我试图将一些 VB.NET 代码转换为 C# 并发现了这个有趣的事情。在 VB.NET 和 C# 中添加两个字符会返回不同的结果。
VB.NET- returns string
VB.NET-返回字符串
Chr(1) & Chr(2) = " "
C#- returns int
C#-返回 int
(char)(1) + char(2) = 3
How can i add(concatenate) two chars in C#?
如何在 C# 中添加（连接）两个字符？
回答by dasblinkenlight
In C# charis a 16-bit numeric type, so +means addition, not concatenation. Therefore, when you add aand byou get a+b. Moreover, the result of this addition is an int(see a quick demo).
在 C# 中char是 16 位数字类型，因此+意味着加法，而不是串联。因此，当您添加a并b获得a+b. 此外，此添加的结果是int（参见快速演示）。
If by "adding two characters" you mean "concatenation", converting them to a strings before applying operator +would be one option. Another option would be using string.Format, like this:
如果“添加两个字符”是指“连接”，则在应用运算符之前将它们转换为字符串+将是一种选择。另一种选择是使用string.Format，像这样：
string res = string.Format("{0}{1}", charA, charB);
回答by xanatos
By adding to an empty string you can force the "conversion" of charto string... So
通过添加到一个空字符串，你可以强制“转换”char到string......所以
string res = "" + (char)65 + (char)66; // AB
(technically it isn't a conversion. The compiler knows that when you add to a stringit has to do some magic... If you try adding nullto a string, it consider the nullto be an empty string, if you try adding a stringit does a string.Concatand if you try adding anything else it does a .ToString()on the non-string member and then string.Concat)
（从技术上讲它不是转换。编译器知道当你添加到 astring它必须做一些魔术......如果你尝试添加null到一个字符串，它认为 thenull是一个空字符串，如果你尝试添加一个stringit做一个string.Concat，如果你尝试添加任何其他东西，它会.ToString()在非字符串成员上做一个，然后string.Concat)
回答by Metalogic
The best answer is in the comments so I want elevate it here to a proper answer. With full credit going to @Jeow Li Huan:
最好的答案在评论中，所以我想在这里将其提升为正确的答案。完全归功于@Jeow Li Huan：
string res = string.Concat(charA, charB);
回答by r.net
(char)(1) has an ascii value of 1 and (char)(2) ascii value of 2
(char)(1) 的 ascii 值为 1， (char)(2) 的 ascii 值为 2
so ascii value of 1 + 2 (i.e. (char)1 + (char)2 ) will be equal to 3.
所以 1 + 2 的 ascii 值（即 (char)1 + (char)2 ）将等于 3。
if you do: "2" + "1" this will give you "21" (althou you should not use this to join strings, bad practice)
如果你这样做：“2”+“1”这会给你“21”（虽然你不应该用它来连接字符串，不好的做法）
if you do: '2' + '1' this will give you int value of 99 that is ascii value of 2 (which is 50) + ascii value of 1(which is 49).
如果你这样做： '2' + '1' 这会给你 99 的 int 值，即 ascii 值 2（即 50）+ ascii 值 1（即 49）。
