Js Custom sorting

Question

I'm trying to sort array of strings ['d', 'CC', 'BB', 'b', 'a', 'Am','AMG'] in such order ["AMG", "Am", "a", "BB", "b", "CC", "d"]

Using

arr.sort(function (a, b) {
  return a.toLowerCase().localeCompare(b.toLowerCase());
});

I get ["a", "Am", "AMG", "b", "BB", "CC", "d"]

because, a < am < amg < b < bb < cc < d - look in a dictionary ... the entry for a comes before the entry for am — Jaromanda X
– Jaromanda X, Commented Jul 14, 2018 at 9:35
You're going to need something fancy then .. because localeCompare makes a < A and you want a > A — Jaromanda X
– Jaromanda X, Commented Jul 14, 2018 at 9:46

Nina Scholz · Accepted Answer · 2018-07-14 10:06:31Z

2

You could chain some sort criteria, after swapping the case of the letters, then

sort by first lower case characters ascending,
sort by length descending
sort by string ascending

function swap(s) {
    return Array.from(s, c => c.toUpperCase() === c ? c.toLowerCase() : c.toUpperCase()).join('');
}

var array = ['d', 'CC', 'BB', 'b', 'bb', 'a', 'Am', 'AMG'];

array.sort((a, b) => {
    var aa = swap(a),
        bb = swap(b);

   return a[0].toLowerCase().localeCompare(b[0].toLowerCase())
       || bb.length - aa.length
       || aa.localeCompare(bb);
});

console.log(array); // ["AMG", "Am", "a", "BB", "b", "CC", "d"]

edited Jul 14, 2018 at 10:06

answered Jul 14, 2018 at 9:44

Nina Scholz

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1 Comment

pavlos Over a year ago

if have ['bb', 'BB'] sort fails ["AMG", "Am", "a", "bb", "BB", "CC", "d"]

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