Storing Data with JavaScript Variables

Before we go any further with JavaScript, 0:01 it's helpful to know that it utilizes different data types. 0:03 As you've seen, JavaScript can work with characters surrounded by quotes and 0:07 does this using its string data type. 0:11 Strings represent sequences of symbols and must be wrapped in quotation marks. 0:15 Besides strings, JavaScript also has other data types. 0:20 The first we'll discuss are numbers. 0:24 These represent real numbers. 0:27 We can use them to keep track of scores and counts and 0:29 perform mathematical operations on them. 0:32 There's also a type called Booleans. 0:36 Booleans represent true and false values and 0:38 come in handy when a program has to make decisions. 0:41 JavaScript has other built in data types and ways to store and keep track of data. 0:45 You'll learn all about those in Treehouse's JavaScript courses. 0:51 Now that we know about different data types, 0:56 let's learn how to use them efficiently in programs. 0:58 Storing data to access or update later is a common task in JavaScript. 1:02 JavaScript allows us to name and reuse values by storing them in variables. 1:08 Think of a variable as a jar with the label indicating what's inside. 1:14 At any time, we can look inside the jar, 1:18 we can even change what's inside the jar or empty it. 1:21 Even though what gets stored in the jar might change, 1:25 it's always the same jar with the label we gave it. 1:28 Just like we can store something inside a jar, 1:32 we can store data inside a JavaScript variable with a unique name. 1:34 Whenever we want to access what's inside that variable, we reference its name. 1:39 Okay, so from that example, 1:46 we know a variable has two parts, a name and a value. 1:48 In JavaScript, the syntax for creating a variable 1:53 requires beginning with the keyword var, let or const. 1:57 Using one of these keywords lets the program know we're preparing to define 2:02 a variable. 2:06 We'll start by using var in this workshop. 2:08 The var keyword is followed by the name we choose for the variable. 2:11 We then use the assignment operator or equal sign, 2:16 which in JavaScript can be used to assign a value. 2:19 Finally, we assign the variable a value, 2:23 which can be any of the types I've mentioned or more. 2:25 For example, we can name a variable with just a single letter and 2:31 set it equal to a value of our choice. 2:35 Normally though, we'll want to use a more 2:39 descriptive variable name to make our programs more readable. 2:41 Let's create a variable to store our favorite foods. 2:45 I'll pick mine, but for practice, I want you to choose your own. 2:50 First in the console, we'll write the var keyword, 2:55 followed by the variable name favoriteFood. 2:58 Next we'll use the assignment operator or 3:06 equal sign to set the variable equal to sushi. 3:09 Now if we press Enter, 3:17 then type the variable name favoriteFood again, and press Enter. 3:18 The value stored in favoriteFood is printed to the console. 3:24 Nice work. 3:27 You've learned one of the building blocks of JavaScript. 3:29 The most powerful programs rely on variables for storing, 3:31 accessing and modifying data. 3:36 Next, we'll go further and use JavaScript to operate on values stored in variables. 3:39

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