Using angular.copy for modal fetch and update of data

gistfile1.txt

angular.module('myApp').service('greeterService',
    ['$log', function($log) {
        var namesSpokenTo = [];
        this.sayHello:  function(name) {
                    namesSpokenTo.push(name);
                    $log.debug('hello, ' + name);
        };
        this.getNames = function() {
           return angular.copy(namesSpokenTo);
        };
        this.replaceNames = function(names) {
            angular.copy(names, namesSpokenTo);
        }
    }]);

    // erase all elements of the array - doesn't 
    // destroy the original, just the copy sent
    // by getNames().
    greeterService.getNames().length = 0;