Functions Examples and Samples

functions.js

//instructions for function will only run when you invoke it
function imAFunction () {
 console.log("hello world");
}

//invoking a function
imAFunction();

//-----------------

// parameters & arguements the example bellow prints the console.log statement with each name
function hello(name) {
    console.log("hello " + name);
}

hello("Jason");
hello("David");

// defined a new variable (should use the parameter defined in the function majority of the time)
let thing = "world";
// passed new variable into hello to make it print Hello world
hello (thing);

//multiple parameters passed into a function
function firstLast(first_name, last_name){
    console.log("hello " + first_name + " " + last_name);
}

let first = "Gaby";
let last = "Frites";
firstLast(first, last);

//-----------------------------
// return sends the value back to the place where you called it
function plus(a, b) {
    let sum = a +b;
    return sum;
}
function multiply(a,b) {
    return a * b;
}

console.log(plus(10,5));

let x = 3 + plus(10,5);
console.log(x);

let y = multiply(plus(10,5), 2);
console.log(y);

//modulous % will equal 0 if it has no remainder otherwise will return the remainder
function isEven(x){
     if (x % 2 === 0) {
         return true;
     } else {
         return false;
     }
}

let num = 9;
if (isEven(num)){
    console.log(num + " is Even");
} else {
    console.log(num + " is Odd");
}