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JavaScript JavaScript Basics (Retired) Working With Numbers Numbers

Posted by johnathanmyers
johnathanmyers
19,994 Points

So I noticed in the following test that when I created a variable that contains a float the number 360.00 is not a float

So I noticed in the following test that when I created a variable that contains a float, the number 360.00 is not a float. So is it safe to assume that just because a "." is used that does not mean that the number is a float if the following numbers to the right of the number equal zero? I can see where this might get tricky if you where programming with money and the program was expecting a float but the amount was an even no change amount. I've been over some other Javascript courses but I never noticed this.

2 Answers

William Li
PLUS
William Li
Courses Plus Student 26,868 Points
William Li
William Li
Courses Plus Student 26,868 Points

It's a float, In fact, every number in JavaScript is just a 64 bit floating point.

johnathanmyers
johnathanmyers
19,994 Points

Thanks William

Marcus Parsons
Marcus Parsons
15,719 Points
Marcus Parsons
Marcus Parsons
15,719 Points

Hey Johnathan,

You can force decimals to display with the normal "toFixed(n)" method where n is the number of decimal places you wish to display, and this works especially well with money since you only want to deal with 2 decimal places. So, let's say there is a transaction between two variables and you want to display in dollars, you can just do like so:

var amt1 = 400;
var amt2 = 40;
var total = "$" + (amt1 - amt2).toFixed(2);
//Displays $360.00
console.log(total);

If you're doing any other currency besides dollars, you can use a library such as the accounting.js library.

johnathanmyers
johnathanmyers
19,994 Points

Thanks Marcus,

Sometimes I think too hard on simple things and my brain breaks. :) I'm adding accounting.js to my bookmarks.

Marcus Parsons
Marcus Parsons
15,719 Points

I know exactly what you mean haha I call those "brain burps" haha It's a great library for dealing with currency!