(JavaScript) 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

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

var success = false;

var sbOriginal = new CkStringBuilder();
success = sbOriginal.LoadFile("qa_data/txt/utf16_emojis_accented_jap.txt","utf-16");
if (success == false) {
    console.log(sbOriginal.LastErrorText);
    return;
}

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

var sb = new CkStringBuilder();
sb.AppendSb(sbOriginal);

// Charset is not used for unicode escaping.  Set it to "utf-8", but it means nothing.
var charsetNotUsed = "utf-8";

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

sb.Encode(encoding,charsetNotUsed);
console.log(sb.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:
sb.Decode(encoding,charsetNotUsed);
console.log(sb.GetAsString());

// -----------------------------------------------------------------------------------------
// Do the same, but use uppercase letters (A-F) in the hex values.
encoding = "unicodeescape-upper";
sb.Encode(encoding,charsetNotUsed);
console.log(sb.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:
sb.Decode(encoding,charsetNotUsed);
console.log(sb.GetAsString());

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

encoding = "unicodeescape-curly";
sb.Encode(encoding,charsetNotUsed);
console.log(sb.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:
sb.Decode(encoding,charsetNotUsed);
console.log(sb.GetAsString());

// -----------------------------------------------------------------------------------------
// Do the same, but use uppercase letters (A-F) in the hex values.
encoding = "unicodeescape-curly-upper";
sb.Encode(encoding,charsetNotUsed);
console.log(sb.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:
sb.Decode(encoding,charsetNotUsed);
console.log(sb.GetAsString());

// -----------------------------------------------------------------------------------------
// HTML hexadecimal character reference

encoding = "unicodeescape-htmlhex";
sb.Encode(encoding,charsetNotUsed);
console.log(sb.GetAsString());

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

// Revert back to the unescaped chars:
sb.Decode(encoding,charsetNotUsed);
console.log(sb.GetAsString());

// -----------------------------------------------------------------------------------------
// HTML decimal character reference

encoding = "unicodeescape-htmldec";
sb.Encode(encoding,charsetNotUsed);
console.log(sb.GetAsString());

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

// Revert back to the unescaped chars:
sb.Decode(encoding,charsetNotUsed);
console.log(sb.GetAsString());

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

encoding = "unicodeescape-plus";
sb.Encode(encoding,charsetNotUsed);
console.log(sb.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
encoding = "unicodeescape-plus-upper";
// ...
// ...

sb.Clear();
sb.AppendSb(sbOriginal);

// -----------------------------------------------------------------------------------------
// Hex in Angle Brackets

encoding = "unicodeescape-angle";
sb.Encode(encoding,charsetNotUsed);
console.log(sb.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.

sb.Clear();
sb.AppendSb(sbOriginal);