Javascript方法调用列表

Question

调用像这样的javascript方法是否正确

 var flag = this.totalSubarrayLengths([ document.getElementsByTagName('ol'), document.getElementsByTagName('ul') ])

 var totalSubarrayLengths = function(container) {
        total = 0;

        for (var val in container) {
            var total += val.length;
        }

        return total;
    }