Javascript: function example

gistfile1.js

/* functions */
/* passing a function as a parameter */
var calculate = function (number, paramTwo, fn) {
    number = number + 3;
    number = number + 1;
    number = number * 8;
  
    return fn(number, paramTwo);
};

/* function parameter for 'fooResult' */
function sum (number, paramTwo) {
    return number + paramTwo;
}

/* function parameter for 'barResult' */
function product (number, paramTwo) {
    return number * paramTwo;
}


var foo = 2, 
    bar = 3;

var fooResult = calculate (foo, 2, sum);
var barResult = calculate (bar, 2, product);

console.log('foo: ' + fooResult);
console.log('bar: ' + barResult);