常见判断是对象还是数组的3种方法

constuctor

<script>
      var fruits = ["Banana", "Orange", "Apple", "Mango"];
      var obj = {};

      function isArray(myArray) {
        return myArray.constructor.toString().indexOf("Array") > -1;
      }

      console.log(isArray(fruits)); //true
      console.log(isArray(obj)); //false
   </script>

Object.prototype.toString.call()

console.log(Object.prototype.toString.call(fruits)); //[Object Array]

instanceof

console.log(fruits instanceof Array);