count - nodef/extra-array GitHub Wiki

Count values which satisfy a test.

Alternatives: count, countEach. Similar: count, segregate.

function count(x, ft)
// x:  an array
// ft: test function (v, i, x)

const xarray = require('extra-array');

var x = [1, 1, 2, 2, 4];
xarray.count(x, v => v % 2 === 1);
// → 2

xarray.count(x, v => v % 2 === 0);
// → 3

References

• List-Extra.count() : Elm
• _.countBy() : Lodash
• Array.count() : Sugar.js
• count-iterable-values : @zeke