检测类型-isArray

        // isArray判断是否为数组
        let arr = [1, 2, 3, 4, 5]
        let arr1 = {
            name: "张三"
        }
        console.log(Array.isArray(arr)); //判断arr是否为数组，返回值：true
        console.log(Array.isArray(arr1));//判断arr1是否为数组，返回值false