内部函数优先级大于形式参数

<script type="text/javascript">
        function f(a){
            console.log(a);// function 
            var a = 2; 
            console.log(a);// 2
            function a(){};
            console.log(a);// 2
        }
        f(1);

    //上述函数预解析的过程如下：
    function f(a){ 
        var a = function(){}; 
        console.log(a);
        // function 
        var a = 2; 
        console.log(a);
        //2
        console.log(a);
        //2
    }
    f(1);

    </script>