Question

var t={a:"1",b:"2"}

is this an Object with properties (a,b)

or it is

a Javascript Labeled Statement ?

Or does it depends on the context ?

what about this ?

I was wondering for why Eval wrap itself with ( )

It is there to resolve confusion. (statement vs expression)

Fine.

But

{"a":"1"} can’t ever be Labeled statement ( because of the " which wraps the a ) , it is illigle and invalid !!!

so it Only be a Object with properties !!!

just as much as
{a:”1″} can only be a Labeled statement and not an object with properties (properties should come with { “ a “:”1″}

So why Eval cant check it ?

Answer 1

var t={a:"1",b:"2"}

is an object with properties a and b.

what about this ?

$.ajax({
    type: 'POST',
    url: '../Handler...',
    dataType: 'json',
    contentType: 'application/json; charset=utf-8',
    data: $.toJSON(jsonObj),
    cache: false,
    ...        
});

This is a call to a function called $.ajax() and passing an object with properties type, url, dataType, contentType, data, cache, … as parameter.

why Eval cant check it ?

Pardon me?