用JavaScript实现斐波拉契数列

<html>
    <head>
        <meta charset="utf-8" />
        <title>html</title>
        <script type="text/javascript">
            function getNthFibonacci(num){
            if(num < 2){
                return num;
            }
            var first = 0;
            var second = 1;
            var third;
            for(var i = 2;i < num;i ++){
                third = first + second;
                first = second;
                second = third;
            }
            return third;
        }
        function output(){
            var number = 10;
            var answer = getNthFibonacci(number);
            document.write(answer);
        }
        </script>
    </head>

    <body>
    </body>
    <script type="text/javascript">output()</script>
</html>

建议不适用递归调用，当数字很大时，递归会非常耗时。