Default value of a type in javascript

Question

Is there a function in JavaScript that returns the default value for a type name that is passed to it? For example:

var defaultValue = built_in_getDefaultValue(\         


        

Answer 1

I don't understand why do you ask such a question. Anyways, the default value of a variable in JavaScript is null or undefined.

For learning purposes, I took this from WikiBooks JavaScript/Variables and Types:

Variables are commonly explicitly declared by the var statement, as shown below:

var c;

The above variable is created, but has the default value of undefined. To be of value, the variable needs to be initialized:

var c = 0;

After being declared, a variable may be assigned a new value which will replace the old one:

c = 1;

But make sure to declare a variable with var before (or while) assigning to it; otherwise you will create a "scope bug."

And now, when you ask why the value is not 0, it is because, even null or undefined are values, which are not defined. Not defined is different from being defined and empty. It might return 0, when the value is declared and not defined.