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{{alias}}( collection, [options,] indicator )
Groups values according to an indicator function and returns group counts.
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: Array|TypedArray|Object
Input collection to group. If provided an object, the object must be
array-like (excluding strings and functions).
options: Object (optional)
Options.
options.thisArg: any (optional)
Execution context.
indicator: Function
Indicator function specifying which group an element in the input
collection belongs to.
Returns
-------
out: Object
Group results.
Examples
--------
> function indicator( v ) {
... if ( v[ 0 ] === 'b' ) {
... return 'b';
... }
... return 'other';
... };
> var collection = [ 'beep', 'boop', 'foo', 'bar' ];
> var out = {{alias}}( collection, indicator )
{ 'b': 3, 'other': 1 }
See Also
--------
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