Methods are like functions that are associated with a particular object.
They are especially helpful when you want to either:
Update the object properties
Calculate something based on an object's properties.
Here, we have included a Circle object, with a radius property representing the circle's radius. We have implemented an areafunction which calculates the circle's area. Notice we have used Math.PI to get the π value.
Instructions
Define a method
perimeter
that calculates the perimeter of a circle.
function Circle (radius) {
this.radius = radius;
this.area = function () {
return Math.PI * this.radius * this.radius;
};
this.perimeter = function () {
return Math.PI * 2 * this.radius;
};
}