reduce - nodef/extra-map GitHub Wiki

Reduce values of set to a single value.

Similar: map, reduce, filter, filterAt, reject, rejectAt.

function reduce(x, fr, acc?)
// x:   a map
// fr:  reduce function (acc, v, k, x)
// acc: initial value

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

var x = new Map(['a', 1], ['b', 2], ['c', 3], ['d', 4](/nodef/extra-map/wiki/'a',-1],-['b',-2],-['c',-3],-['d',-4));
map.reduce(x, (acc, v) => acc+v);
// → 10

map.reduce(x, (acc, v) => acc+v, 100);
// → 110

References