how the browser understand this code

[henry42]

i wrote like this:

var a = function b(){
	return b;
};
alert(a() === a );

and ie6~ie8 return false , ie9 chrome ff return true.
how to explain it?
and

var a = function b(){
};
alert( typeof b );

b is undefined in most of browser but is function in ie6~ie8,
that's why?
thx

[paul_wilkins]

i wrote like this:

var a = function b(){
	return b;
};
alert(a() === a );

and ie6~ie8 return false , ie9 chrome ff return true.
how to explain it?

Internet Explorer doesn't use JavaScript. Instead, it uses their own creation called JScript which is supposed to be the same, but has some bugs in it.

[henry42]

Internet Explorer doesn't use JavaScript. Instead, it uses their own creation called JScript which is supposed to be the same, but has some bugs in it.

thank u very much

[AllanP]

You need to be careful what you are comparing.

var a = function b(){ return typeof b; };
alert(a())
returns function in all browsers
//
alert(typeof a)
returns function in all browsers
//
alert(a() === typeof a)
returns true in all browsers.

However,
var a = function b() { return b; };
returns function b() { return b; }

alert(a() === a ); fails in IE, probably because the layout of the two functions is not exactly the same. You can see this if you look at the return info.