Introduction to Your Tools

Hello and welcome. 0:09 I'm Travis and I'm a teacher here at Treehouse. 0:10 In this course, I'll be introducing you to some very common tools 0:12 available in almost every programming language. 0:16 Whether you're completely new to programming or have written some code 0:19 before, you'll find these concepts invaluable on your coding journey. 0:22 When going through this course, 0:29 I want you to think of Java learning a new foreign language. 0:30 I'll introduce you to the rules, or syntax, of the language as you need it. 0:34 Just as you would learn a foreign language through immersion, 0:38 you'll naturally start recognizing patterns 0:41 and concepts that repeat across different parts of code. 0:43 Don't worry if you encounter unfamiliar terms or expressions. 0:47 That's a normal part of the learning process. 0:51 We'll focus on one concept at a time, and while I might occasionally ask you 0:53 to temporarily skip over certain bits of code, I promise we'll circle 0:57 back to them when the time is right. 1:01 So let's start our Java journey the same way you'd begin 1:05 learning a foreign language, by learning how to introduce ourselves. 1:07 Our first program will be simple but meaningful. 1:11 We'll write code to display, hello, my name is, and then your name on the screen. 1:14 Now before we write our first line of code, 1:19 let me introduce you to our coding environment, Workspaces. 1:21 Look for the Launch Workspace button right beneath the video. 1:24 Go ahead and click it, 1:27 and a new browser window will open with everything you need to start coding. 1:28 Let's go! 1:32 Alright, welcome to your Workspace. 1:34 It's all set up and ready for you. 1:36 On the side there a list of all the files available to you in this Workspace 1:38 I already created a file to get us started 1:43 called Introductions.java. Let's open it up and take a look 1:45 Right here, you'll see a note. 1:51 This is called a comment. 1:53 In Java, comments start with two forward slashes. 1:54 Everything after these slashes is ignored by Java when it runs your program. 1:58 Programmers use comments to explain what their code 2:03 does in plain English or to leave notes for others. 2:05 One important goal in programming is to write code that's clear 2:09 enough to not need any comments. 2:12 But since you're just starting out, please feel free to add comments 2:14 whenever you want to remind yourself what your code is doing. 2:17 Now, remember I said I may ask you to skip over some parts until later? 2:20 Right now, that's what we'll do with most of the code you see on the screen. 2:24 It's setup code that every Java program needs, 2:28 and I've already taken care of it for you, 2:31 so don't worry if it doesn't make sense quite yet. 2:33 There is really only one line I want you to focus on for now, this one right here. 2:36 You don't need to understand exactly how it works just yet. 2:40 What's important is that this line creates something called a Java object. 2:43 Don't worry, we'll explain objects in detail later. 2:48 This object has a special function, 2:51 called a method, which lets us write text to the terminal down here. 2:53 If for some reason you don't see a terminal at the bottom, 2:58 you can come up here to View and select Show Console and it should pop in for you. 3:00 I know I just mentioned some new terms objects and methods. 3:06 Don't worry if they sound complicated. 3:09 We'll explore them step by step as we go. 3:11 For now, just keep familiarizing yourself with the language. 3:14 I'll explain these ideas when they become relevant. 3:17 So thanks to the setup I've done, we have access to this object called Console. 3:20 We can use this to write text on the screen. Objects have methods 3:25 that let them perform actions. We want to print text and the method for 3:29 that is called printf. Here's how we do it. 3:33 First type console with a lowercase c, 3:37 then a dot to access its methods, 3:40 followed by the name of the method, printf. 3:43 To call a 3:46 method, we add a pair of opening and closing parentheses. 3:47 Inside these parentheses, we can add some double quotes 3:51 and inside of those you can write the text you want to print. 3:54 So let's write, hello my name is Travis. 3:57 You can put your name in there of course though. 4:00 We then finish 4:05 with a semicolon to end the statement. 4:06 You may have noticed a small dot showing up in the tab 4:09 when I started editing the file. 4:12 This means there are unsaved changes. 4:14 Now to save the file I'll click file and then save. 4:16 But as you can see, you can also quickly save by using 4:19 the shortcut Command-S on Mac or Control-S on Windows. 4:22 That's what I'll be using going forward. 4:26 Java is a compiled language, which means 4:31 we need to run a program called a compiler to turn our human-readable Java code 4:33 into computer-readable code before we'll be able to run it. 4:38 To do this, we go to the console and type 4:42 the command javac Introductions.java 4:45 In this command, 4:53 javac stands for java compiler. 4:53 This tells the compiler to convert the code 4:57 in Introductions.java into an executable file. 5:00 I'll press enter now. 5:03 If we list the files 5:08 in this folder by typing ls, 5:09 We see a new file called Introductions.class. 5:13 You could also right in the sidebar here and click 5:17 refresh. 5:19 By the way, 5:23 ls means list, and it shows all the files in the current folder. 5:24 We'll be using some terminal commands 5:28 this throughout the course, and I'll explain them as we go. 5:30 If you want to learn more about using the terminal, 5:33 check out our terminal course 5:35 which I've linked in the teacher's notes below this video. 5:36 Okay, next, to run our program, we type java Introductions. 5:40 Notice this time the command is java, without the c. 5:47 The java command runs the program. 5:50 Also, we only type the class name introductions, without the extension. 5:53 Java c required us to type the .java extension, this java command does not. 5:57 I'll press enter, 6:03 and here on the screen we see the output. 6:05 Nice! 6:07 You've just compiled and run your first Java program. 6:10 You're learning a lot already. 6:12 Before we learn even more, 6:14 let's do an exercise to review what we've covered so far. 6:15 But first, I want to remind you about the Treehouse community. 6:19 If you have questions, chances are someone else 6:23 has already had the same question and maybe even found an answer. 6:25 Learning how to ask questions as well as looking for answers 6:29 is one of the best ways to learn. 6:32 And also, if you already have some Java experience, 6:34 you might be familiar with IDEs, or Integrated Development Environments. 6:37 These tools make coding easier with features code completion, and 6:42 while IDEs are great, I encourage you to keep following along in this workspace. 6:46 Doing things manually helps build your confidence and understanding 6:51 by removing some of the magic that IDEs provide. 6:55 We'll explore IDEs in a future course when the time is right. 6:58

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