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I get myself in to trouble about "this instanceof function(){}", how "this" will be so this expression values true?

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  I get myself in to trouble about "this instanceof function(){}", how "this" will be so this expression values true? PinYang Yuen <21sanguitar@gmail.com> - 2014-03-20 23:06 -0700
    Re: I get myself in to trouble about "this instanceof function(){}", how "this" will be so this expression values true? Joao Rodrigues <groups_jr-1@yahoo.com.br> - 2014-03-21 05:42 -0300
      Re: I get myself in to trouble about "this instanceof function(){}", how "this" will be so this expression values true? PinYang Yuen <21sanguitar@gmail.com> - 2014-03-21 02:45 -0700

#23611 — I get myself in to trouble about "this instanceof function(){}", how "this" will be so this expression values true?

Function.prototype.bind = function(thisObject) {
        var func = this;
        var args = Array.prototype.slice.call(arguments, 1);
        var Nop = function() {}; // Nop: not otherwise provided for
        var bound = function() {
            var a = args.concat(Array.prototype.slice.call(arguments));
            return func.apply(
                this instanceof Nop ? this : thisObject || window, a);
        };
        Nop.prototype = func.prototype;
        bound.prototype = new Nop();
        return bound;
    };

this instanceof Nop ?

Many thanks in advance:-)

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#23612

On 21-03-2014 03:06, PinYang Yuen wrote:
> Function.prototype.bind = function(thisObject) {
>          var func = this;
>          var args = Array.prototype.slice.call(arguments, 1);
>          var Nop = function() {}; // Nop: not otherwise provided for
>          var bound = function() {
>              var a = args.concat(Array.prototype.slice.call(arguments));
>              return func.apply(
>                  this instanceof Nop ? this : thisObject || window, a);
>          };
>          Nop.prototype = func.prototype;
>          bound.prototype = new Nop();
>          return bound;
>      };
>
> this instanceof Nop ?
>
> Many thanks in advance:-)
>

The right polyfill for Function.prototype.bind (ES5.1, § 15.3.4.5) is 
given in the following MDN article:

<https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/bind>


-- 
Joao Rodrigues

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#23613

在 2014年3月21日星期五UTC+8下午4时42分56秒，J.R.写道：
> On 21-03-2014 03:06, PinYang Yuen wrote:
> 
> > Function.prototype.bind = function(thisObject) {
> 
> >          var func = this;
> 
> >          var args = Array.prototype.slice.call(arguments, 1);
> 
> >          var Nop = function() {}; // Nop: not otherwise provided for
> 
> >          var bound = function() {
> 
> >              var a = args.concat(Array.prototype.slice.call(arguments));
> 
> >              return func.apply(
> 
> >                  this instanceof Nop ? this : thisObject || window, a);
> 
> >          };
> 
> >          Nop.prototype = func.prototype;
> 
> >          bound.prototype = new Nop();
> 
> >          return bound;
> 
> >      };
> 
> >
> 
> > this instanceof Nop ?
> 
> >
> 
> > Many thanks in advance:-)
> 
> >
> 
> 
> 
> The right polyfill for Function.prototype.bind (ES5.1, § 15.3.4.5) is 
> 
> given in the following MDN article:
> 
> 
> 
> <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/bind>
> 
> 
> 
> 
> 
> -- 
> 
> Joao Rodrigues

thanks. I found i don't make myself clear. The real problem is how instanceof op works? I finally figure it out.

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