HTML Entity for Uppercase C Double Struck (ℂ)
What You'll Learn
How to display the uppercase C double struck (ℂ) in HTML using named entity, hexadecimal, decimal, and CSS escape methods. This mathematical symbol denotes the set of complex numbers in algebra and analysis, commonly written as ℂ in equations such as z ∈ ℂ. It is U+2102 in the Letterlike Symbols block (U+2100–U+214F).
Render it with ℂ, ℂ, ℂ, or CSS escape \2102. The named entity ℂ is often the most readable option; &Complexes; is a semantic alias for the same character. See also math entities.
⚡ Quick Reference — Uppercase C Double Struck Entity
U+2102Letterlike Symbols
ℂHexadecimal reference
ℂDecimal reference
ℂAlso &Complexes;
Name Value
──────────── ──────────
Unicode U+2102
Hex code ℂ
HTML code ℂ
Named entity ℂ (alias &Complexes;)
CSS code \2102
Meaning Double-struck capital C (complex numbers)
Related U+0043 = plain C; U+010A = Ċ (C dot above)
Block Letterlike Symbols (U+2100–U+214F)Complete HTML Example
A simple example showing the uppercase C double struck (ℂ) using hexadecimal code, decimal HTML code, the named entity, and a CSS content escape:
<!DOCTYPE html>
<html>
<head>
<style>
#point:after{
content: "\2102";
}
</style>
</head>
<body>
<p>Symbol (hex): ℂ</p>
<p>Symbol (decimal): ℂ</p>
<p>Symbol (named): ℂ</p>
<p id="point">Symbol (CSS): </p>
</body>
</html>🌐 Browser Support
The uppercase C double struck (ℂ) and the named entity ℂ are supported in all modern browsers:
👀 Live Preview
See the uppercase C double struck (ℂ) in mathematical notation:
C (U+0043) or Ċ (C dot above)🧠 How It Works
Hexadecimal Code
ℂ uses the Unicode hexadecimal value 2102 to display the character. The x prefix indicates hexadecimal format.
Decimal HTML Code
ℂ uses the decimal Unicode value 8450 to display the same character. A common method for Letterlike Symbols.
Named Entity
ℂ is the standard named entity for ℂ—readable in source HTML. &Complexes; is a semantic alias for the same character.
CSS Entity
\2102 is used in CSS stylesheets, particularly in the content property of pseudo-elements like ::before and ::after.
Same visual result
All four methods produce the glyph: ℂ. Unicode U+2102 sits in Letterlike Symbols. Do not confuse with plain C (U+0043) or Ċ (C dot above, U+010A). Use math-friendly fonts for best rendering.
Use Cases
The uppercase C double struck (ℂ) is commonly used in:
Denote the set of complex numbers ℂ in algebra, analysis, and engineering mathematics.
Represent number sets alongside ℝ (reals), ℚ (rationals), and ℤ (integers) in mathematical notation.
Textbooks, online courses, and tutorials explaining complex numbers and field extensions.
Research papers, theses, and journal articles in mathematics, physics, and engineering.
Equation editors, calculators, and interactive math apps that render set notation in HTML.
Signal processing, control theory, and physics content using complex-valued functions.
Showcase Letterlike Symbols and math font coverage in type design demos.
💡 Best Practices
Do
- Use
ℂor&Complexes;in HTML when possible for readability - Serve pages as UTF-8; you can also type ℂ directly in UTF-8 source
- Use math-friendly fonts (e.g. Cambria Math, STIX Two Math) for clear double-struck rendering
- Use fonts that support Letterlike Symbols characters
- Distinguish ℂ (U+2102) from plain
C(U+0043) and Ċ (C dot above)
Don’t
- Substitute plain
Cwhen ℂ is required for correct mathematical notation - Confuse ℂ (double-struck) with Ċ (C dot above—different character)
- Put CSS escape
\2102in HTML text nodes - Assume all fonts render Letterlike Symbols identically
- Omit UTF-8 encoding on pages with accented characters
Key Takeaways
Four references render ℂ; named entity is most readable
ℂ ℂ ℂFor CSS stylesheets, use the escape in the content property
\2102Unicode U+2102 — DOUBLE-STRUCK CAPITAL C
Essential for complex numbers, set theory, and mathematical content
Previous: Uppercase C Dot Above (Ċ) Next: Uppercase C Hook (Ƈ)
❓ Frequently Asked Questions
ℂ (named), ℂ (hex), ℂ (decimal), or \2102 in CSS content. The named entity ℂ is the most readable for HTML content.U+2102 (DOUBLE-STRUCK CAPITAL C). Letterlike Symbols block. Hex 2102, decimal 8450. Commonly used to represent the set of complex numbers.ℂ or ℂ) or the named entity ℂ is used in HTML content. The CSS entity (\2102) is used in CSS, e.g. in the content property of pseudo-elements. Both produce ℂ but in different contexts.ℂ and &Complexes; render ℂ (U+2102). &Complexes; is a semantic alias that explicitly denotes the set of complex numbers.ℂ. &Complexes; is an alias for the same character. You can also use ℂ or ℂ for numeric references.Explore More HTML Entities!
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