count

Counts values which satisfy a test.

Alternatives: one, all.

iterable.count(x, fn, [ths]);
// x:   an iterable
// fn:  test function (v, i, x)
// ths: this argument

const iterable = require('extra-iterable');

var x = [1, 1, 2, 2, 4];
iterable.count(x, v => v % 2 === 0);
// 3

references

• count-iterable-values: @zeke
• _.countBy(): lodash
• List-Extra.count(): elm