this 指向

  1. // this 指向问题
  2. function fun() {
  3.   var self = this;
  4.   self.name = name||'default';
  5.   return {
  6.     show : function(){
  7.       console.log(1, self.name)
  8.     },
  9.     setName: function (name) {
  10.       self.name = name;
  11.       return this;
  12.     }
  13.   }
  14. }
  15. var obj = fun()
  16. console.log(2, obj.setName('sdf').show())
  18. console.log(3, fun().show())

闭包

  1. // 闭包问题
  2. var addCount;
  3. function s1() {
  4.   var count = 0;
  5.   function s12() {
  6.     console.log(count)
  7.   }
  9.   addCount = function() {
  10.     count++;
  11.   };
  13.   return s12
  14. }
  15. var result1 = s1();
  16. var result2 = s1();
  17. addCount();
  18. result1();
  19. result2();