排序-将数字和特殊字符移到末尾

Question

I am trying to sort an array which looks like this:

var arr = ["a", "c", "1", "e", "-", "4", "p", "$", "~", "6", "33", "h"];

the order I want to get should be:

var arr = ["a", "c", "e", "h", "p", "-", "~", "$", "1", "33", "4", "6"];

I already have a working solution but I am not sure if this is the best (fastest) way how to do it.

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

for (var i = 0; i < arrLength; i++) {
    if (arr[i].localeCompare("a") >= 0) {
        if (i > 0) {
            Array.prototype.push.apply(arr, arr.splice(0, i));
        }

        break;
    }
}

Answer 1

Yes, you should include the logic in the comparison function. This will be easier to understand than first sorting by one criteria and then shifting around parts of the array by some other criteria, and it will be reusable in other situations.

You want

arr.sort(function(a, b) {
    var aIsAlphabetical = a.localeCompare("a") >= 0,
        bIsAlphabetical = b.localeCompare("a") >= 0;
    if (!aIsAlphabetical && bIsAlphabetical)
        return 1;
    if (aIsAlphabetical && !bIsAlphabetical)
        return -1;
    return a.localeCompare(b);
});

or, shortened:

arr.sort(function(a, b) {
    return (b.localeCompare("a")>=0)-(a.localeCompare("a")>=0) || a.localeCompare(b);
});

If you're looking for fastest code, you should set up a benchmark at the targetted system with a good example array.