Welshman Docs / @welshman/lib / countBy
Function: countBy() ​
countBy<
T,K>(f,xs):Map<K,number>
Defined in: packages/lib/src/Tools.ts:641
Counts array elements by key function
Type Parameters ​
T ​
T
K ​
K
Parameters ​
f ​
(x) => K
Function to generate group key
xs ​
T[]
Array to count entries
Returns ​
Map<K, number>
Map of counts