JavaScript typeOf()

functiontestTypeOf()

{

   console.log(typeof 111);//number

   console.log(typeof 'test');//string

   console.log(typeof false);//bolean

   console.log(typeof [1,2,3,4]);//object

   console.log(typeof {name:'John', age:34});//object

   person=null;

   console.log(typeof(person));//object

   person=undefined;

   console.log(typeof(person));//undefined

   console.log(null ===undefined);//false

   console.log(null ==undefined );//true

}