Question

var s = "Hi";

Date.now = function (){
    return new Date();
}

s.createdOn = function (){
    return new Date();
}

alert(s.createdOn()); // This is not working
alert(Date.now()); // This works fine

Am i violating any rule. Because i can add new property to Date class but not to string class. why?

Answer 1

The reason you can’t add properties or methods to a string literal is that when you try to access a literal’s property or method, the Javascript interpreter temporarily copies the value of the string into a new object and then use that object’s properties or methods. This means a String literal can only access a string’s default properties or methods and those that have been added as prototypes.

More info can be obtained from this link:

http://www.hunlock.com/blogs/The_Complete_Javascript_Strings_Reference

Hope this will help you

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