Using the variable “name” doesn't work with a JS object

Question

The behaviour can be seen in this little snippet (execute it as a global script):

var name = {};
name.FirstName = \'Tom\';
alert(name.FirstName);
         


        

Answer 1

Your name variable is actually window.name, because top-level variables declared with var are attached to the global object.

The HTML5 spec requires that window.name is a DOMString. This means that the value of window.name can only be a sequence of characters, not an object.

In Chrome, an attempt to use window.name to store anything except a primitive string will coerce the value to a primitive string. For example:

window.name = {};
window.name === "[object Object]"; // true

You can avoid this problem by using a name variable that is not in the top-level scope:

(function() {
    var name = {};
    // this `name` is not `window.name`
    // because we're not in the top-level scope

    console.log(name);
})();