$let
Reference group: Utility expressions and variables
What it does
Defines scoped variables referenced with $$name.
Syntax
{$let: { vars: { name: expression }, in: expression }}
Use case
Avoid repeating complex expressions.
$let: practical example
{ $project: { total: { $let: { vars: { subtotal: { $multiply: ["$price", "$quantity"] } }, in: { $add: ["$$subtotal", "$shipping"] } } } }💡 Explanation
Defines scoped variables referenced with
$$name.
When to use it
Avoid repeating complex expressions.Key Takeaways
- Defines scoped variables referenced with
$$name. - Typical use: Avoid repeating complex expressions.