External module "utils/count-by/docs/types/index.d"

Export assignment countBy

• countBy(collection: Collection, indicator: Indicator): any
• countBy(collection: Collection, options: Options, indicator: Indicator): any

• Groups values according to an indicator function and returns group counts.

  Notes

  • When invoked, the indicator function is provided two arguments:

    • value: collection value
    • index: collection index

  • The value returned by an indicator function should be a value which can be serialized as an object key.

  • If provided an empty collection, the function returns an empty object.

  Parameters

  • collection: Collection

    input collection

  • indicator: Indicator

    indicator function specifying which group an element in the input collection belongs to

  Returns any

  counts

  Example

  function indicator( v ) {
      return v[ 0 ];
  }
  var arr = [ 'beep', 'boop', 'foo', 'bar' ];
  
  var out = countBy( arr, indicator );
  // returns { 'b': 3, 'f': 1 }

• Groups values according to an indicator function and returns group counts.

  Notes

  • When invoked, the indicator function is provided two arguments:

    • value: collection value
    • index: collection index

  • The value returned by an indicator function should be a value which can be serialized as an object key.

  • If provided an empty collection, the function returns an empty object.

  Parameters

  • collection: Collection

    input collection

  • options: Options

    function options

  • indicator: Indicator

    indicator function specifying which group an element in the input collection belongs to

  Returns any

  counts

  Example

  function indicator( v ) {
      return v[ 0 ];
  }
  var arr = [ 'beep', 'boop', 'foo', 'bar' ];
  
  var out = countBy( arr, indicator );
  // returns { 'b': 3, 'f': 1 }