1     <script> 2          3         var m = "roboce"; 4         if(m === "roboce"){ 5             var k = "haha"; 6         } 7          8         var a = function() { 9             var aa = "aa";10         }11         12         function f1() {13             var bb = "bb";14         }15         console.log(k); // haha16         console.log(aa); // undefined17         console.log(bb); // undefined18     </script>