在另一个函数JavaScript中访问函数参数

Question

How to access function's parameter in another function that invoke it, here's what I mean

function one(a){
  b();
}

function b(){
  //'a' is the parameter of function one
  if(a>0){
   //do some stuff
  }
}

//the parameter 'a' of function one goes here to catch an event
element.addEventListener('wheel', one);

Can I access function one parameter in function b?

Answer 1

Pass the parameter into b as well

function one(a){
  b(a);
}

function b(a){
  //'a' is the parameter of function one
  if(a>0){
   //do some stuff
  }
}

Answer 2

You have to pass a to function b as follows.

function one(a){
  b(a);
}

function b(a){
  //'a' is the parameter of function one
  if(a>0){
   //do some stuff
  }
}

//the parameter 'a' of function one goes here to catch an event
element.addEventListener('wheel', one);