Question

I have this function that returns an object:

String.prototype.test = function(a,b){
    var ob = {};
    ob[a] = b;
    return this || ob
}

//usage
"Test".test('hi','hello');

If .hi isnt attached to test, i want it to return the string.

So with that example I would need:

"Test".test('hi','hello').hi;//returns: hello

To work, but then I also need:

"Test".test('hi','hello'); //returns Test

To work, I tried using || in the return but it’s not working. Thanks for the help.

Answer 1

It’s impossible to make the return value depend on what happens with the returned value.

You could however return a String object with a property hi:

Don’t do this in any production code, it’s extremely ugly and nobody expects it.

String.prototype.doStuffThatNobodyExpects = function(a, b) {
    var s = new String(this);
    s[a] = b;
    return s;
};

Again, don’t do this in any production code, it’s extremely ugly and nobody expects it.

Demo:

js> var s = 'Test'.doStuffThatNobodyExpects('hi', 'hello');
js> print(s);
Test
js> print(s.hi);
hello