(Visual FoxPro) Unicode Escape and Unescape Text in StringBuilder

Demonstrates options for unicode escaping non-us-ascii chars and emojis.

Note: This example requires Chilkat v11.1.0 or greater.

For more information, see https://www.chilkatsoft.com/unicode_escape.asp

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL lnSuccess
LOCAL loSbOriginal
LOCAL loSb
LOCAL lcCharsetNotUsed
LOCAL lcEncoding

lnSuccess = 0

loSbOriginal = CreateObject('Chilkat.StringBuilder')
lnSuccess = loSbOriginal.LoadFile("qa_data/txt/utf16_emojis_accented_jap.txt","utf-16")
IF (lnSuccess = 0) THEN
    ? loSbOriginal.LastErrorText
    RELEASE loSbOriginal
    CANCEL
ENDIF

* The above file contains the following text, which includes some emoji's,
* Japanese chars, and accented chars.

loSb = CreateObject('Chilkat.StringBuilder')
loSb.AppendSb(loSbOriginal)

* Charset is not used for unicode escaping.  Set it to "utf-8", but it means nothing.
lcCharsetNotUsed = "utf-8"

* Indicate the desired format/style of Unicode escaping.
* Choose JSON-style (JavaScript-style) Unicode escape sequences by using "unicodeescape"
lcEncoding = "unicodeescape"

loSb.Encode(lcEncoding,lcCharsetNotUsed)
? loSb.GetAsString()

* Output:
* \ud83e\udde0
* \ud83d\udd10
* \u2705
* \u26a0\ufe0f
* \u274c
* \u2713
* \u4e2d
* \u00e9 xyz \u00e0
* abc \u79c1 \u306f \u3093 ghi

* Revert back to the unescaped chars:
loSb.Decode(lcEncoding,lcCharsetNotUsed)
? loSb.GetAsString()

* -----------------------------------------------------------------------------------------
* Do the same, but use uppercase letters (A-F) in the hex values.
lcEncoding = "unicodeescape-upper"
loSb.Encode(lcEncoding,lcCharsetNotUsed)
? loSb.GetAsString()

* Output:
* \uD83E\uDDE0
* \uD83D\uDD10
* \u2705
* \u26A0\uFE0F
* \u274C
* \u2713
* \u4E2D
* \u00E9 xyz \u00E0
* abc \u79C1 \u306F \u3093 ghi

* Revert back to the unescaped chars:
loSb.Decode(lcEncoding,lcCharsetNotUsed)
? loSb.GetAsString()

* -----------------------------------------------------------------------------------------
*  ECMAScript (JavaScript) �code point escape� syntax

lcEncoding = "unicodeescape-curly"
loSb.Encode(lcEncoding,lcCharsetNotUsed)
? loSb.GetAsString()

* Output:
* \u{d83e}\u{dde0}
* \u{d83d}\u{dd10}
* \u{2705}
* \u{26a0}\u{fe0f}
* \u{274c}
* \u{2713}
* \u{4e2d}
* \u{00e9} xyz \u{00e0}
* abc \u{79c1} \u{306f} \u{3093} ghi

* Revert back to the unescaped chars:
loSb.Decode(lcEncoding,lcCharsetNotUsed)
? loSb.GetAsString()

* -----------------------------------------------------------------------------------------
* Do the same, but use uppercase letters (A-F) in the hex values.
lcEncoding = "unicodeescape-curly-upper"
loSb.Encode(lcEncoding,lcCharsetNotUsed)
? loSb.GetAsString()

* Output:
* \u{D83E}\u{DDE0}
* \u{D83D}\u{DD10}
* \u{2705}
* \u{26A0}\u{FE0F}
* \u{274C}
* \u{2713}
* \u{4E2D}
* \u{00E9} xyz \u{00E0}
* abc \u{79C1} \u{306F} \u{3093} ghi

* Revert back to the unescaped chars:
loSb.Decode(lcEncoding,lcCharsetNotUsed)
? loSb.GetAsString()

* -----------------------------------------------------------------------------------------
* HTML hexadecimal character reference

lcEncoding = "unicodeescape-htmlhex"
loSb.Encode(lcEncoding,lcCharsetNotUsed)
? loSb.GetAsString()

* Output:
* 🧠
* 🔐
* ✅
* ⚠️
* ❌
* ✓
* 中
* é xyz à
* abc 私 は ん ghi

* Revert back to the unescaped chars:
loSb.Decode(lcEncoding,lcCharsetNotUsed)
? loSb.GetAsString()

* -----------------------------------------------------------------------------------------
* HTML decimal character reference

lcEncoding = "unicodeescape-htmldec"
loSb.Encode(lcEncoding,lcCharsetNotUsed)
? loSb.GetAsString()

* Output:
* 🧠
* 🔐
* ✅
* ⚠️
* ❌
* ✓
* 中
* é xyz à
* abc 私 は ん ghi

* Revert back to the unescaped chars:
loSb.Decode(lcEncoding,lcCharsetNotUsed)
? loSb.GetAsString()

* -----------------------------------------------------------------------------------------
* Unicode code point notation or U+ notation

lcEncoding = "unicodeescape-plus"
loSb.Encode(lcEncoding,lcCharsetNotUsed)
? loSb.GetAsString()

* Output:
* u+1f9e0
* u+1f510
* u+2705
* u+26a0u+fe0f
* u+274c
* u+2713
* u+4e2d
* u+00e9 xyz u+00e0
* abc u+79c1 u+306f u+3093 ghi

* Chilkat cannot unescape the Unicode code point notation or U+ notation.
* For this style, Chilkat only goes in one direction, which is to escape.

* To emit uppercase hex, specify unicodeescape-plus-upper
lcEncoding = "unicodeescape-plus-upper"
* ...
* ...

loSb.Clear()
loSb.AppendSb(loSbOriginal)

* -----------------------------------------------------------------------------------------
* Hex in Angle Brackets

lcEncoding = "unicodeescape-angle"
loSb.Encode(lcEncoding,lcCharsetNotUsed)
? loSb.GetAsString()

* Output:
* <1f9e0>
* <1f510>
* <2705>
* <26a0><fe0f>
* <274c>
* <2713>
* <4e2d>
* <e9> xyz <e0>
* abc <79c1> <306f> <3093> ghi

* Chilkat cannot unescape the angle bracket notation.
* For this style, Chilkat only goes in one direction, which is to escape.

loSb.Clear()
loSb.AppendSb(loSbOriginal)

RELEASE loSbOriginal
RELEASE loSb