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JavaScript JavaScript Basics (Retired) Working With Numbers Doing Math

Posted by Kevin Fernandez-Gonzalez
Kevin Fernandez-Gonzalez
16,790 Points

I don't get what I'm getting wrong

I don't get what I'm doing wrong any pointers.

script.js 
var wholesalePrice = 5.45;
var retailPrice = 9.99;
var quantity = 47;
var salesTotal = retailPrice * quantity;
var profit = saleTotal - wholesalePrices * quantity ;
index.html 
<!DOCTYPE HTML>
<html>
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
  <title>JavaScript Basics</title>
</head>
<body>
<script src="script.js"></script>
</body>
</html>

2 Answers

Cheryl Oliver
Cheryl Oliver
21,676 Points
Cheryl Oliver
Cheryl Oliver
21,676 Points

You need to put brackets around wholesale and quantity. That is because you need to multiply wholesalePrice and quantity BEFORE you subtract. If you dont put brackets around it will subtract and then multiply.

var wholesalePrice = 5.45;

var retailPrice = 9.99;

var quantity = 47;

var salesTotal = retailPrice * quantity;

var profit = salesTotal - (wholesalePrice * quantity);

Steven Parker
Steven Parker
231,271 Points
Steven Parker
Steven Parker
231,271 Points

Actually, the parentheses are not necessary.

Like most languages, JavaScript has rules for "operator precedence". Since multiplication (*) takes precedence over subtraction (-), it will be performed first even if it comes later in the expression.

But with that said, it can also be good practice to use parentheses just to make your intentions clear, or to make a complicated expression more readable, even when they are not necessary to get the correct result.

See this MDN page for more information on operator precedence.

Steven Parker
Steven Parker
231,271 Points
Steven Parker
Steven Parker
231,271 Points

You have a couple of spelling errors:

  • you wrote "saleTotal" (singular) instead of "salesTotal"
  • you wrote "wholesalePrices" (plural) instead of "wholesalePrice"