将Unicode字符转换为扩展ASCII

Question

我有一些二进制数据，必须对其进行百分比编码才能通过长度受限制的查询字符串参数传输到远程服务。

回到我身上，其中一些值的编码如下：

\u2014

我希望将此值转换回二进制数据。 Unicode字符与扩展ASCII中的原始值相同。

如何将以上内容转换回扩展ASCII？ 编辑：Windows-1252

我希望使用Javascript解决方案，但可以使用：PHP，Python，C，C ++。

Answer 1

这是映射：

var windows1252 = [
         0x0000,0x0001,0x0002,0x0003,0x0004,0x0005,0x0006,0x0007,0x0008,0x0009,0x000A,0x000B,0x000C,0x000D,0x000E,0x000F
        ,0x0010,0x0011,0x0012,0x0013,0x0014,0x0015,0x0016,0x0017,0x0018,0x0019,0x001A,0x001B,0x001C,0x001D,0x001E,0x001F
        ,0x0020,0x0021,0x0022,0x0023,0x0024,0x0025,0x0026,0x0027,0x0028,0x0029,0x002A,0x002B,0x002C,0x002D,0x002E,0x002F
        ,0x0030,0x0031,0x0032,0x0033,0x0034,0x0035,0x0036,0x0037,0x0038,0x0039,0x003A,0x003B,0x003C,0x003D,0x003E,0x003F
        ,0x0040,0x0041,0x0042,0x0043,0x0044,0x0045,0x0046,0x0047,0x0048,0x0049,0x004A,0x004B,0x004C,0x004D,0x004E,0x004F
        ,0x0050,0x0051,0x0052,0x0053,0x0054,0x0055,0x0056,0x0057,0x0058,0x0059,0x005A,0x005B,0x005C,0x005D,0x005E,0x005F
        ,0x0060,0x0061,0x0062,0x0063,0x0064,0x0065,0x0066,0x0067,0x0068,0x0069,0x006A,0x006B,0x006C,0x006D,0x006E,0x006F
        ,0x0070,0x0071,0x0072,0x0073,0x0074,0x0075,0x0076,0x0077,0x0078,0x0079,0x007A,0x007B,0x007C,0x007D,0x007E,0x007F
        ,0x20AC,0xFFFD,0x201A,0x0192,0x201E,0x2026,0x2020,0x2021,0x02C6,0x2030,0x0160,0x2039,0x0152,0xFFFD,0x017D,0xFFFD
        ,0xFFFD,0x2018,0x2019,0x201C,0x201D,0x2022,0x2013,0x2014,0x02DC,0x2122,0x0161,0x203A,0x0153,0xFFFD,0x017E,0x0178
        ,0x00A0,0x00A1,0x00A2,0x00A3,0x00A4,0x00A5,0x00A6,0x00A7,0x00A8,0x00A9,0x00AA,0x00AB,0x00AC,0x00AD,0x00AE,0x00AF
        ,0x00B0,0x00B1,0x00B2,0x00B3,0x00B4,0x00B5,0x00B6,0x00B7,0x00B8,0x00B9,0x00BA,0x00BB,0x00BC,0x00BD,0x00BE,0x00BF
        ,0x00C0,0x00C1,0x00C2,0x00C3,0x00C4,0x00C5,0x00C6,0x00C7,0x00C8,0x00C9,0x00CA,0x00CB,0x00CC,0x00CD,0x00CE,0x00CF
        ,0x00D0,0x00D1,0x00D2,0x00D3,0x00D4,0x00D5,0x00D6,0x00D7,0x00D8,0x00D9,0x00DA,0x00DB,0x00DC,0x00DD,0x00DE,0x00DF
        ,0x00E0,0x00E1,0x00E2,0x00E3,0x00E4,0x00E5,0x00E6,0x00E7,0x00E8,0x00E9,0x00EA,0x00EB,0x00EC,0x00ED,0x00EE,0x00EF
        ,0x00F0,0x00F1,0x00F2,0x00F3,0x00F4,0x00F5,0x00F6,0x00F7,0x00F8,0x00F9,0x00FA,0x00FB,0x00FC,0x00FD,0x00FE,0x00FF
];

var unicodeToWindows1252 = {};

for( var i = 0; i < windows1252.length; ++i ) {
    unicodeToWindows1252[String.fromCharCode(windows1252[i])] = i;
}

我不知道在js中表示二进制的意思，但是我使用的是普通数组并将Windows-1252字节值推入整数。

var str = "\u2014";

var character, i = 0;
var ret = [];
while( character = str.charAt(i++) ) {
    if( !(character in unicodeToWindows1252 ) ) {
        throw new TypeError( character + " is unrepresentable in windows-1252, unable to convert" );
    }
    ret.push( unicodeToWindows1252[character] );
}
console.log( ret ) //[151]
//ret contains the integer 151, which is Windows-1252 for "\u2014"