In MongoDB, the $sort aggregation pipeline stage sorts all input documents and returns them to the pipeline in sorted order.
Tag: what is
MongoDB $switch
In MongoDB, the $switch aggregation pipeline operator evaluates a series of case expressions, and executes a specified expression only when a case expression evaluates to true.
MongoDB $mergeObjects
In MongoDB, the $mergeObjects aggregation pipeline operator combines multiple documents into a single document.
MongoDB $isArray
In MongoDB you can use the $isArray aggregation pipeline operator to check whether or not a value is an array.
It accepts any valid expression, and returns true if the expression is an array, false if it’s not.
MongoDB $literal
In MongoDB, the $literal aggregation pipeline operator returns a value without parsing.
It accepts any valid expression, and returns the unparsed expression.
The $literal operator can be useful for when you have a value that MongoDB could inadvertently interpret as an expression, but you don’t want it to.
For example, if you have a monetary amount that includes a dollar sign, MongoDB might inadvertently interpret that as a field name. You can use $literal to prevent MongoDB from interpreting such expressions.
MongoDB $ln
In MongoDB, the $ln aggregation pipeline operator calculates the natural logarithm (ln) of a number and returns the result as a double.
MongoDB $log
In MongoDB, the $log aggregation pipeline operator calculates the log of a number in the specified base and returns the result as a double.
MongoDB $indexOfCP
In MongoDB, the $indexOfCP aggregation pipeline operator searches a string for an occurrence of a substring and returns the UTF code point index of the first occurrence.
The UTF code point index is zero-based (i.e. it starts at 0).
MongoDB $indexOfBytes
In MongoDB, the $indexOfBytes aggregation pipeline operator searches a string for an occurrence of a substring and returns the UTF-8 byte index of the first occurrence.
The UTF byte index is zero-based (i.e. it starts at 0).
MongoDB $indexOfArray
In MongoDB, the $indexOfArray aggregation pipeline operator searches an array for an occurrence of a specified value and returns the array index of the first occurrence.