--- title: Methods slug: methods docTags: createdAt: 2023-01-27T02:56:13.000Z --- # Methods Methods are special types of [Functions](docId\:IZsyKLqFBEtmslMltBMay) that apply to a [List](docId\:xWH_cUkHj9waqaEfb7H71) or Sequence of data. Usually, methods are used to aggregate data – such as counting or summing List values. ### Syntax Methods are called like this, where `subject` is the subject of the method, such as the List or Sequence that is being aggregated: `subject.methodName(parameter1, parameter2)` If the method is passed an Expression as a parameter, you can use either of the following syntaxes -- they both mean the same thing: `subject.methodName({expression})` ` subject.methodName{expression}` The second is often preferred, for clarity and brevity. Methods can be chained together to form a pipeline of evaluations -- for example: ` subject.methodName1{expression1}.methodName2{expression2}` ### Example Usages Methods can be used anywhere in Carrot. Most commonly, methods will operate on a List – for example, to calculate the total number of shares from the [Grants](docId\:Lpx5L8w1t54iPBqq8Eqjv) field, only counting grants that have a strike price of less than 10 cents, one could write: `grants.filter{price < .1}.sum{shares}` ### Method List | **Method** | **Description** | | ------------------------------------------ | -------------------------------------------------------------------------------------------------------------------- | | `.all()` | Returns true if all of the items match an expression | | `.any()` | Returns true if at least one of the items matches an expression | | \`.count() | Returns the number of items matching an expression | | \`.filter() | Returns a list of items that match an expression | | [.find()](docId:6Mwj2HJZ9ljkHmBfK0VVo) | When called against a Table, queries for entities in that table matching the expression | | \`.groupBy() | *Generally only used in Dashboards*. Groups the items by key, returning a SequenceGroupedBy, that can be aggregated. | | \`.join() | Returns a string that joins the items together. | | \`.limit() | Returns a list of items, with the number of the items limited to a certain number. | | \`.map() | Returns a list of items that have been transformed using the mapping expression passed in. | | \`.max() | Returns the maximum value of the items in the list, excluding nulls. | | \`.mean() | Returns the arithmetic mean (average) of the items in the list, excluding nulls. | | \`.min() | Returns the minimum value of the items in the list, excluding null. | | \`.none() | Returns true if none of the items matches an expression. | | \`.sort() | Returns a list of items, sorted by an expression. | | \`.sortDesc() | Returns a list of items, sorted in descending order. | | `.sum()` | Returns the sum of the items (optionally transformed with an expression). | | [.unique()](docId\:OYypYkrFY06bRSVJBFETI) | Returns a list filtered down to its unique items | # Aggregators (deprecated) Aggregators are special expressions used to aggregate values over time, only used in ChartHop Dashboards. However, **aggregators are now deprecated.** We recommend that you replace their use with the corresponding ChartHop methods above. The Dashboards UI will be migrated to use Methods instead. ### Syntax An aggregator in Carrot appears as a word followed by curly brackets, which contain an expression. `aggregator{expression}` An aggregator performs a calculation on the parameter expression and returns a [Number](https://docs.charthop.com/ucI5-number) value based on the aggregator's logic. All aggregators are case-insensitive. ### Usage Aggregators are only available in Dashboards. ### Migration To replace the use of an Aggregator currently used in a Dashboard with a Method call instead, use the following syntax: `db.job.find(jobFilter).aggregator{expression}` For example, this aggregator call: `count{headcount if department:engineering}` Becomes: `db.job.find{department:engineering}.count{headcount}` ### Aggregator List | **Aggregator** | **Description** | | ---------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [count\{}](https://docs.charthop.com/count) | Counts the number of times a given expression evaluates to a truthy value. All non-truthy values, such as `null`, an empty string, `0`, or `false` are discarded. | | [max\{}](https://docs.charthop.com/max) | Returns the largest value of a given expression. All non-numeric values are discarded. | | [mean\{}](https://docs.charthop.com/yOFs-mean) | Returns the average of all values of a given expression. All non-numeric values are discarded. | | [min\{}](https://docs.charthop.com/exqD-min) | Returns the smallest value of a given expression. All non-numeric values are discarded. | | [sum\{}](https://docs.charthop.com/sum) | Returns the sum of all values of a given expression. All non-numeric values are discarded. |