Variable operators

Operators used to perform variable operations.

$let

Binds variables for use in the specified expression, and returns the result of the expression.

{
  "$let": {
    "vars": { "var": "any", "var": "any", "...": "..." },
    "in": "expression"
  }
}

expry({
  $let: {
    vars: { age: 24 },
    in: { isAdult: { $gte: ["$$age", 18] } },
  },
}); // { isAdult: true }