Sort array by specific key

sort.js

function sortByKey(arr, key) {
    function compare(n, m){
        return (m.localeCompare(n, 'fa') >= 0)
    }
    return arr.sort(function(a, b) {
        var x,
            y;    
        x = a[key];
        y = b[key];        
        return ((check(x, y)) ? -1 : ((check(y, x)) ? 1 : 0));
    });
}