syntax function javascript code example

Example 1: javascript function

function myFunc(theObject) {
  theObject.make = 'Toyota';
}

var mycar = {make: 'Honda', model: 'Accord', year: 1998};
var x, y;

x = mycar.make; // x gets the value "Honda"

myFunc(mycar);
y = mycar.make; // y gets the value "Toyota"
                // (the make property was changed by the function)

Example 2: javascript function

// variable:
var num1;
var num2;
// function:
function newFunction(num1, num2){
	return num1 * num2;
}

Example 3: javascript function

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
// FUNCTION DECLARATION (invoking can be done before declaration)
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
function calcAge1(birthYear) {
   return 2037 - birthYear;
}
const age1 = calcAge1(1991);

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
// FUNCTION EXPRESSION (invoking canNOT be done before declaration)
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
const calcAge2 = function (birthYear) {
   return 2037 - birthYear;
}
const age2 = calcAge2(1991);

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
// ARROW FUNCTION (generally used for one-liner functions)
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
const calcAge3 = birthYear => 2037 - birthYear;
const age3 = calcAge3(1991);
console.log(age3);