如何獲取已被JavaScript的.bind（）函數綁定的參數

Question

如何獲取已綁定到函數的參數？

function add(x){ 
    return x + 1 
} 

var func = add.bind(null, x) 
// how do I get the value of `x` from the `func` variable alone? 

Answer 1

var claser = function(x) { 

    var internalX = x; 

    this.add = function(adderValue) { 
     internalX += adderValue; 
    } 
    this.getX = function() { 
     return internalX; 
    } 
} 

var theX = 5; // Setting X 
var cls = new claser(theX); 

cls.add(1); // Adding X 

var gettingX = cls.getX(); // Getting X 
alert(gettingX); 

這是你需要什麼？