javascript判断对象

 var assert = require('chai').assert;

 describe('Array', function() {
   describe('#indexOf()', function() {
     it('should return -1 when the value is not present', function() {

         var obj = {};
         var array  = [];
         var date = new Date();

         var fn = function() {
         }

         var _null = null;

         assert.equal('[object Object]', Object.prototype.toString.call(obj));
         assert.equal('[object Array]', Object.prototype.toString.call(array));
         assert.equal('[object Date]', Object.prototype.toString.call(date));
         assert.equal('[object Function]', Object.prototype.toString.call(fn));

         assert.equal('[object Null]', Object.prototype.toString.call(_null));
     });
   });
 });