[MUSIC] 0:00 This practice session covers basic JavaScript functions. 0:04 It's a great followup to the fifth part of the JavaScript Basics course. 0:07 If you haven't taken that yet, and find this practice session too difficult, 0:11 then go through the first five parts of that course first. 0:15 I've added a link in the teacher's notes below. 0:18 For this practice session, you'll write four functions. 0:20 Call those functions and output the results to the console. 0:23 It's pretty simple but combines the basics of creating and 0:27 using JavaScript functions. 0:30 I've attached a workspace to this video which includes some starter files and 0:31 instructions. 0:35 Open up the workspace and open up the geometry.js file. 0:36 You'll see six instructions listed as JavaScript comments. 0:39 Here's what you should do. 0:43 First attach the JavaScript file to the index.html file. 0:45 After all, the program won't work at all unless the web page loads it. 0:48 Next create a function that calculates the area of a rectangle. 0:52 To calculate the area of a rectangle, you multiply the width by the height. 0:56 So this function needs to accept two arguments, 1:01 do some math, then return the results back. 1:04 Then you'll create another function to calculate the volume 1:06 of a rectangular prism. 1:09 Also known as a box. 1:11 For that, you multiply the width by the height by the length. 1:13 This function should return the volume. 1:16 Now the next two functions involve calculating the area of a circle and 1:19 the volume of a sphere. 1:23 These both require using the JavaScript math object to get the value of pi. 1:24 And to use a method that lets you raise the number to a certain power. 1:29 For example x to the second power or x squared. 1:33 Now I didn't cover those in JavaScript basics course, so 1:37 you'll need to do a bit of research to figure out how to use them. 1:40 I've included links in the teacher's notes below. 1:43 Okay so if you have the radius of a circle to calculate the area of a circle, 1:46 you take pi times the radius squared. 1:51 Squared is also refered as the second power or to the second power. 1:54 So the function will receive a radius value and return the area. 1:58 The last function will calculate the volume of a sphere. 2:02 To do that you multiply four thirds by pi, by the radius cubed or 2:05 the radius to the third power. 2:09 Okay now finally you'll add four lines to log out 2:11 the results of your function to the JavaScript console. 2:15 It's not super exciting to look at, but this is what your output should look like, 2:19 something like this. 2:23 Now if you wanna do some quick study before tackling this practice session. 2:24 In the teacher's notes look for 2:27 links to videos that can help you solve this challenge. 2:29 But if you're ready, go for it. 2:31 Program your solution and I'll show you my solution in the next video. 2:33