js precompiled link variable declaration to enhance the function declaration to enhance the overall

Precompiled tetralogy
1. Create AO objects
2 to find the parameter and variable declaration, the variable parameter name and attribute name as AO, is undefined
3. The arguments and parameters unified
4. find the function body function declarations , the value of the function imparting member

function fn(a){
     console.log(a) //function a(){}
     var a = 123;
     console.log(a)//123
     function a(){}
     console.log(a)//123
     var b = function(){}
     console.log(b) //function(){}
     
}
fn(1)