01_js数据类型

JavaScript数据类型：

<script type="text/javascript">
            var age = 30; //number
            var nikename = 'zhangsan' //string
            var result = true; //真假
            var teshu = undefined; //未赋值
            var teshu2 = null; 
            
            
            //判断数据类型
            console.log(typeof(age));
            console.log(typeof(nikename));
            console.log(typeof(teshu));
            console.log(typeof(teshu2));
</script>