$substrBytes
Reference group: String aggregation expressions
What it does
Extracts by byte offsets.
Syntax
{$substrBytes: [string, start, count]}
Use case
Byte-oriented parsing.
Important notes
May split a multibyte character.
$substrBytes: practical example
{ $project: { prefix: { $substrBytes: ["$code", 0, 4] } } }💡 Explanation
Extracts by byte offsets.
When to use it
Byte-oriented parsing.
Caution
May split a multibyte character.
Key Takeaways
- Extracts by byte offsets.
- Typical use: Byte-oriented parsing.