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Learn Go: Variables and Types
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  1. 1
    Programs, like the ones we write in Go, are excellent at processing and performing operations on data. But in programming, “data” can be so many different things. Data can be numbers, boolean value…
  2. 2
    In Go, values can be many things. Just to name a few, values can be numbers (like 109), or text wrapped in quotes (like “Hello world”). These values can be written into code as is, and are called _…
  3. 3
    In addition to literal (aka unnamed) values, there are also named values. Naming a value in Go means creating a word that will represent that value. One example of named values are constants,…
  4. 4
    Programming languages need to process and organize data. That data is stored as binary numbers (numbers consisting of 0’s and 1’s) in the memory of your computer. In this way, binary numbers are us…
  5. 5
    Go has 15 different numeric types that fall into the three categories: int, float, and complex. That means there are fifteen different ways to describe a number in Go. This includes 11 different in…
  6. 6
    Now that we have some background on what types are, we can talk about what variables are and how we make and use them. A variable is a named value (like a constant) with the added feature that it c…
  7. 7
    There is no shame in having your code fail to run. Programming errors and exceptions happen all the time and learning to read them and understand them is an indispensable tool in a programmer’s too…
  8. 8
    Variables are placeholder names that we use to refer to values that we intend to update over the course of our program. Updating our variable is also called assigning a value to a variable. In or…
  9. 9
    We’ve talked about numeric types so far, but Go offers a few other built-in types. One particularly useful type is called a string. A string is Go’s type for storing and processing text. In a gen…
  10. 10
    Even before we assign anything to our variables they hold a value. Go’s designers attempted to make these “sensible defaults” that we can anticipate based on the variable’s types. All numeric varia…
  11. 11
    There is a way to declare a variable without explicitly stating its type using the short declaration := operator. We might use the := operator if we know what value we want our variable to store wh…
  12. 12
    There is one more common way to define an int in Go. Computers actually have a default length for the data in their Read-Only Memory (ROM). Some newer comps may have more processing power and can s…
  13. 13
    Variables are different from constants because we can update them. This update feature becomes incredibly important when we need to use the original value of a variable for a calculation (or any ge…
  14. 14
    So far we’ve been declaring variables one by one, each on their own separate line. But Go actually allows us to declare multiple variables on a single line, in fact, there’s a few different syntaxe…
  15. 15
    In this lesson you learned: How to use literals in a Go program. How to create constants that give names to values. The basic types in Go: ints, floats, complexs, and strings. The different…
  1. 1
    fmt is one of Go’s core packages. We’ve used it for print information to the terminal using the method fmt.Println(). fmt has a broader purpose, helping us format data, which is why it’s sometime…
  2. 2
    fmt.Println() allows us to print to the terminal and view the data that we’re working with. It has some defaulting styling built-in that makes viewing data easier for us. fmt.Println() prints its _…
  3. 3
    Using fmt.Println() and fmt.Print() we have the ability to concatenate strings, i.e. combine different strings into a single string: guess := “C” fmt.Println(“Is”, guess, “your final answer?”) //…
  4. 4
    In addition to %v, Go has a variety of useful verbs (check their documentation for a comprehensive list). Let’s go over a few in this exercise, starting …
  5. 5
    While we’ve been using fmt methods to print things out, remember, it’s the formatter package. We have other methods that don’t print strings, but format them instead like fmt.Sprint() and fmt.Sprin…
  6. 6
    If we need to interpolate a string, without print it, then we can use fmt.Sprintf(). Just like fmt.Printf() counterpart, fmt.Sprintf() can also use verbs: correctAns := “A” answer := fmt.Sprintf…
  7. 7
    Another helpful method from the fmt package is .Scan() which allows us to get user input! Let’s see an example of this in action: fmt.Println(“How are you doing?”) var response string fmt.Scan(…
  8. 8
    Wonderful work getting through the fmt package’s methods! There are many more methods that we didn’t include, but you can read through Go’s fmt documentation for more…

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