How to make chainable function in JavaScript?

Question

Lets imagine function like this:

function foo(x) {
    x += \'+\';
    return x;
}

Usage of it would be like:

var x, y;
x =         


        

Answer 1

If I remember correctly, you can use "this" as a context of a function (object it belongs to) and return it to make the function chainable. In other words:

var obj = 
{
    f1: function() { ...do something...; return this;},
    f2: function() { ...do something...; return this;}
}

then you can chain the calls like obj.f1().f2()

Keep in mind, you won't be able to achieve what you are expecting by calling obj.f1().toUpperCase() - it will execute f1(), return "this" and will try to call obj.toUpperCase().