判断字段是否为空

function isEmpty(v) {
            switch (typeof v) {
                case 'undefined':
                    return true;
                case 'string':
                    if (v.replace(/(^[  ]*)|([  ]*$)/g, '').length == 0) return true;
                    break;
                case 'boolean':
                    if (!v) return true;
                    break;
                case 'number':
                    if (isNaN(v)) return true;
                    break;
                case 'object':
                    if (null === v || v.length === 0) return true;
                    for (var i in v) {
                        return false;
                    }
                return true;
            }
            return false;
        }
原文地址:https://www.cnblogs.com/HePandeFeng/p/12867441.html