JavaScript編程作用域鏈實踐

Question

我做從nodeschool.io的JavaScript的做法，我是給這個代碼：

var a = 1, b = 2, c = 3; 
 

 
(function firstFunction(){ 
 
\t var b = 5, c = 6; 
 

 
\t (function secondFunction(){ 
 
\t \t var b = 8; 
 

 
\t \t (function thirdFunction(){ 
 
\t \t \t var a = 7, c = 9; 
 

 
\t \t \t (function fourthFunction(){ 
 
\t \t \t \t var a = 1, c = 8; 
 

 
\t \t \t })(); 
 
\t \t })(); 
 
\t })(); 
 
})();

我不能夠訪問這裏面，所以我嘗試任何事情它是這樣的：

var a = 1, b = 2, c = 3; 
 

 
var start = (function firstFunction(){ 
 
\t var b = 5, c = 6; 
 

 
\t var secondFunction = (function secondFunction(){ 
 
\t \t var b = 8; 
 

 
\t \t (function thirdFunction(){ 
 
\t \t \t var a = 7, c = 9; 
 

 
\t \t \t (function fourthFunction(){ 
 
\t \t \t \t var a = 1, c = 8; 
 

 
\t \t \t })(); 
 
\t \t })(); 
 

 
\t \t return { 
 
\t \t \t secondFunction: secondFunction, 
 
\t \t \t printB: function() { 
 
\t \t \t \t return b; 
 
\t \t \t } 
 
\t \t } 
 

 
\t })(); 
 

 
\t return { 
 
\t \t printC: function() { 
 
\t \t \t return c; 
 
\t \t } 
 
\t } 
 

 
})(); 
 

 
console.log("a: " + a + ", b: " + start.secondFunction.printB() + ", c: " + start.printC());

我不知道我的方法是否正確，但我一直堅持這一整天。你會如何解決這個問題，爲什麼我的代碼不能進入secondFunction.printC？

Answer 1

嘗試類似這樣的事情。

var a = 1, b = 2, c = 3; 

var start = (function firstFunction(){ 
    var b = 5, c = 6; 
    var obj = {}; 

    (function secondFunction(){ 
    var b = 8 
    obj.secondFunction = function(){ 
     return b; 
    }; 
    (function thirdFunction(){ 
     var a = 7, c = 9; 
     obj.thirdFunction = function(){ 
      return c; 
     }; 
     (function fourthFunction(){ 
      var a = 1, c = 8; 
      obj.fourthFunction = function(){ 
       return c; 
      }; 
     })(); 
    })(); 
    })(); 
    return obj 
})(); 

console.log (start.secondFunction())