countAs

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Subhajit Sahu edited this page Feb 4, 2021 · 14 revisions

Counts occurrences of values. 🏃 📼 📦 🌔 📒

Alternatives: count, countAs.

entries.countAs(x, fm);
// x:  entries
// fm: map function (v, k, x)
// --> Map {value => count}

const entries = require("extra-entries");

var x = [["a", 1], ["b", 1], ["c", 2], ["d", 2], ["e", 4]];
entries.countAs(x);
// Map(3) { 1 => 2, 2 => 2, 4 => 1 }

var x = [["a", 1], ["b", 2], ["c", 3], ["d", 4]];
entries.countAs(x, v => v % 2);
// Map(2) { 1 => 2, 0 => 2 }

references