(Delphi ActiveX) Decode JSON Unicode Escaping

Demonstrates how to decode JSON Unicode escaped strings.

JSON escaping with hexadecimal encoding, also known as "JSON Unicode escaping," is a way to represent special characters and non-ASCII characters within a JSON (JavaScript Object Notation) string using hexadecimal Unicode code points. This encoding is commonly used when you need to include characters that are outside the ASCII character set or when you want to represent characters in a more compact form.

In JSON Unicode escaping, special characters are represented using the '\u' escape sequence followed by a four-digit hexadecimal number that represents the Unicode code point of the character. Here are some examples:

• '\u0022': Represents a double quote ('"') character.
• '\u005C': Represents a backslash ('\') character.
• '\u003C': Represents a less-than ('<') character.
• '\u003E': Represents the greater-than ('>') character.

For example, if you have a JSON string containing '>' and '<', you would represent it using Unicode escape sequences like this:

Original String: ""
JSON Escaped String: "\u003chtml\u003e"

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
s: WideString;
sb: TChilkatStringBuilder;
sDecoded: WideString;

begin
s := '\u003chtml\u003e';

sb := TChilkatStringBuilder.Create(Self);
sb.Append(s);
sb.Decode('json','utf-8');

sDecoded := sb.GetAsString();

Memo1.Lines.Add(sDecoded);
end;