JavaScript - How do I learn about “closures” usage?

Question

From Wikipedia, the free encyclopedia: Closure (computer science)

In computer science, a closure is a function that is evaluated in an

Answer 1

A practical example of closures is when they are used to create "Private" variables, like

function incrementer(){
    var i=0;
    this.increment=function(){
        i++;
    }
    this.get=function(){
        return i;
    }
}

The only way to access i is to use the method get, and the only way to change it is to use the method increment. In classes, you can do this to emulate private variables.