在JavaScript中将Unicode转换为ASCII

Question

In c#, I have ö ASCII character 148 . but when I change like

 char convstr = (char)148;

It returns \” . Its "”" .Its unicode.

If I want it back ASCII code, I just use Strings.Asc("”") . It will return to 148.

So How can I get from "”" to 148 in JavaScript?

I tried Like that=>

"”".charCodeAt(0) but it return 8221 . I think its Unicode.

And If you don't mind, please explain to me why char convstr = (char)148; return \” also. I am also stuck in there.

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Answer 1

148 isn't the value for ö in ASCII (ie the 7-bit US ASCII encoding that goes only up to 127) nor the commonly-referred-to-as-ASCII codepages 1252 (Windows Latin 1) and ISO/IEC 8859-1 . 1252 has ” in that location while the ISO codepage has nothing. That value is used for ö only in the old DOS codepages, 437 and 865.

Windows, .NET and C# strings are Unicode natively. This pages proves this - StackOverflow is an ASP.NET site. You can convert data in non-Unicode encodings easily, either through the Encoding class, or by specifying the encoding when loading data from streams with a StreamReader.

For example, this will convert the byte value 148 to ö using the 437 codepage :

var result=Encoding.GetEncoding(437).GetString(new byte[]{148});
Debug.Assert(result=="ö");

While this returns ” :

var result=Encoding.GetEncoding(1252).GetString(new byte[]{148});

The StreamReader(string,Encoding) overload and its variants can load data from files using the specified encoding, eg :

using(var reader=new StreamReader(path,Encoding.GetEncoding(437)))
{
    var line=reader.ReadLine();
    ....
}