var a = ["a", "b", "c", ""]; the calculated result of
is
{
a:3,
b:2,
c:1}
var a = ["a", "b", "c", ""]; the calculated result of
is
{
a:3,
b:2,
c:1}
var a = ['a', '', '', '', 'b', '', '', 'c', ''];
let b = a.reduce((d, v) => void (v ? (d.k = v) && (d.v[v] = 0) : d.v[d.k] += 1) || d, {v: {}, k: ''}).v;
console.log(b);((a, _) => a.reduce((p, c) =>
[_ = c || _, _ && [p[_] = p[_] || 0, !c && (p[_] PP)], p][2], {}))
(["a","","","","b","","","c",""], undefined)ignores all empty characters before the first non-null character.
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