U+222E "∮" Contour Integral Unicode Character
Unicode Version 17.0
∮
U+222E "∮" Contour Integral is a mathematical symbol used to denote a line integral taken over a closed curve or contour, most frequently encountered in complex analysis and vector calculus, where it represents the integration of a function around a loop. Its design features a standard integral sign with a small circle in the center, specifically indicating that the path of integration forms a closed loop, which is essential in theorems like Cauchy's integral formula and Stokes' theorem.
General Properties
| Code Point | U+222E |
| Version Added | 1.1 |
| Name | Contour Integral |
| Block | Mathematical Operators |
| General Category | Math Symbol |
| Canonical Combining Class | Not Reordered |
| Bidirectional Class | Other Neutral |
| Mirrored | Yes |
Encodings
| HTML Decimal Encoding | ∮ |
| HTML Hex Encoding | ∮ |
| UTF-8 Encoding | 0xE2 0x88 0xAE |
| UTF-16 Encoding | 0x222E |
| UTF-32 Encoding | 0x0000222E |
| C/C++/Java Escape | \u222e |