$strLenCP (Code-Point Length)

Last updated: 2026-10-09

$strLenCP (Code-Point Length)

$strLenCP returns the number of Unicode code points in a string — essentially the character count people perceive. Chinese, Japanese, and emoji each count as 1, making it right for nickname limits or text summaries. Unlike byte-counting $strLenBytes, multi-byte characters do not inflate the result. Note composite characters (e.g. skin-tone emoji) may span several code points.

📝 Syntax

{ $strLenCP: <string-expression> }

⚙️ Parameters

Returns：The code-point length as an integer.

▶ Example

Run the commands below in your local mongosh (requires a running mongod):

// $strLenCP: validate nickname length
 db.users.aggregate([
  { $project: { len: { $strLenCP: '$nickname' } } }
])

Output：

{ "_id": 1, "len": 4 }
{ "_id": 2, "len": 2 }

📌 Notes

• One Chinese character or emoji counts as 1 code point
• Composite characters (e.g. skin-tone emoji) may span multiple code points
• For storage bytes, use $strLenBytes

🏷️ Related Tags

💡 Related Cases

📚 Related Tutorials

❓ FAQ

Web-Tutorial Tech Team

A team of developers maintaining programming tutorials. Each tutorial is written and reviewed by developers with expertise in that field. We work to keep our content accurate and reliable — if you spot an issue, please let us know.

About Us