When a function is stored as a property of object, we call it a "method". When a method is invoked, "this" is bound to that object. If an invocation expression contains a refinement (that is, a "." expression or [subscript]expression), it is invoked as a method: //Show code... A method can use "this" to access to object so that it can retrieve v…

the_method_invocation_pattern.js

//Create myObject. It has a value and an increment method.
//The increment method takes a optional parameter.
//If the argument is not a number, then 1 is used as the default.

var myObject = {
  value:     0,
  increment: function(inc){
    this.value +=
      typeof inc === 'number' ? inc : 1;
  }
};

console.log(myObject.value);  //Show 0

myObject.increment(20);
console.log(myObject.value);  //Show 20

myObject.increment("bad param");
console.log(myObject.value); //Show 21