function2.js

//the function from before
function sum(number1, number2) {
    console.log(number1 + number2);
}
//sum(2, 1); //3

//new function that takes 3 parameters
function doesSomething(parameter1, parameter2, parameter3) { //again we define a function with 3 parameters
    console.log('This is parameter 1: ',parameter1); //print parameter 1
    console.log('This is parameter 2: ',parameter2);//print parameter 2
    console.log('The result is:');
    parameter3(parameter1,parameter2); //invoke parameter 3 and pass on parameter 1 and parameter 2 as arguments
}

doesSomething(4,5,sum); //invoke the function, prints out 9