可變自調用函數

Question

我不知道里面不確定爲什麼它的不確定，如果我聲明，像這樣：

var mainBtn = $('.main-button'), 
    cloneFund = (function(mainBtn) { 
     console.log(mainBtn); // undefined 
     return arguments.callee; 
    })(); 

甚至：

var btn = $('.main-button'), 
    cloneFund = (function(btn) { 
     console.log(btn); // undefined 
     return arguments.callee; 
    })(); 

Answer 1

你應該有：

var btn = $('.main-button'), 
    cloneFund = (function(btn) { 
     console.log(btn); // undefined 
     return arguments.callee; 
})(btn); // need to add the argument when invoked 

Answer 2

你要通過mainBtn工作。

var mainBtn = $('.main-button'), 
 
    cloneFund = (function(mainBtn) { 
 
     console.log(mainBtn); // available 
 
     return arguments.callee; 
 
    })(mainBtn); // here you have to pass

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> 
 
<button class="main-button">Main Button</button>