Find duplicated ID's width jQuery.js

(function ($) {
    var ids = [],
        sorted = [],
        repeated = [];
    
    $('[id]').each(function () {
        ids.push(this.id);
    });
    
    var sorted = ids.sort();
    
    for (var i = 0; i < ids.length - 1; i++) {
        if (sorted[i + 1] == sorted[i]) {
            repeated.push(sorted[i]);
        }
    }
    
    repeated.length && console.log('Duplicated IDs(' + repeated.length +'): ' + repeated);
})(jQuery);