匿名函数递归(arguments.callee)和命名函数递归

匿名函数递归

 function factorial(num) {

             if (num <= 1) {

                 return 1;

             } else {

                 return num * arguments.callee(num - 1);

             }

         }

命名函数递归

 function factorial(num) {
             if (num <= 1) {
                 return 1;
             } else {
                 return num * factorial(num - 1);
             }
         } 

调用函数

 var trueFactorial = factorial;

         factorial = function () {

             return 0;

         };

         console.log(trueFactorial(5));

         console.log(factorial(5));