1 function getFnName(fn){
 2 return typeof fn !== ‘function‘?
 3        undefined:
 4        fn.name ||
 5       /function (.+)\(/.exec(fn + ‘‘)[1]
 6 }
 7 
 8 
 9 function Person(){}
10 
11 var i = new Person();
12 
13 var name = getFnName(i.constructor);
14 
15 alert(name)