Nested Functions in Javascript
In JavaScript it is perfectly normal to have functions inside functions. The function within another function body, is called as nested function.
The nested function is private to the container function and cannot be invoked from outside the container function.
Demo :
<html>
<head>
<style>
div#maincontent {
height: 220px;
width: 500px;
border: 1px solid #CEE2FA;
text-align: left;
color: #08438E;
font-family: calibri;
font-size: 20;
padding: 5px;
}
div#heading {
text-decoration: bold;
text-align: center;
margin-top: 80px;
width: 500px;
border: 1px solid #CEE2FA;
text-align: center;
color: #08438E;
background-color: #CEE2FA;
font-family: calibri;
font-size: 20;
padding: 5px;
}
h2 {
padding: 0;
margin: 0;
}
</style>
</head>
<body>
<center>
<div id="heading">
<h2>Booking Summary</h2>
</div>
<div id="maincontent">
<script>
var seats = 3;
var costPerTicket = 320;
var cost = 0; //Requirement 5:Code for total cost calculation is moved to function calculateCost
calculateCost(seats); //Requirement 3 a:Handling cost calculation inside the function
function calculateCost(tickets) {
var discountedCost;
document.write(
"Actual cost per ticket: Rs." + costPerTicket + "<br>"
);
if (tickets > 2 && tickets <= 6) {
//Requirement 3 b:Discount calculation is performed in a separate function
calculateDiscount(tickets); //cost = cost + discountedCost;
} else if (tickets > 6) {
document.write(
"<br>Oops!You cannot book more than 6 tickets!!<br>"
);
} else {
cost = tickets * costPerTicket;
document.write(
"<br><br>" + "Amount payable: Rs." + cost + "<br>"
);
}
} //Requirement 3 b:Handling discount calculation inside function calculateDiscount
function calculateDiscount(tickets) {
var discount = 10;
const percent = 100;
document.write(
"<br>" +
tickets +
" seats are eligible for festive discount!!" +
"<br>"
);
for (index = 1; index <= tickets; index++) {
discountedCost =
costPerTicket - (discount / percent) * costPerTicket;
cost = cost + discountedCost;
document.write(
"<br>" + discount + " % discount!" + " on Ticket " + index
);
discount = discount + 10;
}
document.write("<br><br>" + "Amount payable: Rs." + cost + "<br>");
}
</script>
</div>
</center>
</body>
</html>