Data Types 1

In this chapter, we will overview how to store data in variables and the basic data types available, which include strings, numbers, and booleans.

Variables#

Before we go over data types, we will cover how to store data and refer to it later. We can do this by using variables. A variable is a way to store a value and give it a name, to which you can refer back to later.

In Custom Commands, you define a variable by starting with a $, its name, and the assignment operator :=. To illustrate this, consider the following example:

{{ $name := "Alice" }}
{{ $age := 42 }}
{{ $isCool := true }}

{{ $name }}, aged {{ $age }}, is cool: {{ $isCool }}

Later on, we may wish to reassign a new value to a variable. We can do this by using the re-assignment operator =. When and why this becomes necessary will be discussed in a later chapter.

{{ $name := "Alice" }}
{{ printf "%T" $name }}

Data Types#

If you’re completely new to programming, you might not know what a data type is. You can think of a data type as a way to distinguish between different kinds of things. As a real-life analogy, you can separate food into several categories, such as fruits, vegetables, and meat. Each category is in that sense its own data type.

In programming, we have similar categories, such as numbers, strings, and booleans (true / false values). Each of these categories has its own set of operations that can be performed on them. For instance, you can add two numbers together, but you cannot add two strings together (at least not in the way you might expect).

Strings#

A string is a sequence of zero or more characters. You can generally think of it as a word or a sentence. In the bot’s template actions, you can create a string by enclosing some text in double quotes ("). For instance, "Hello, world!" is a string. We call those double-quoted strings.

Now, here we might run into a problem quite quickly: what if we want to include a double quote in our string? We can’t just write "Peter said "Hello, world!"", as the bot would think the string ends at the quotes before Hello and not know that we want them included in the string. To solve this, we must escape the double quote by adding a backslash (\) in front of it. This tells the bot that the double quote is not the end of the string. In other words, "Peter said \"Hello, world!\"" would yield the expected result.

To insert a newline (you would press Enter on your keyboard), you can use the escape sequence \n. For example the string "Hello\nWorld!" would result in the following output:

Hello
World!

For a full list of escape sequences, you can refer to the Go documentation. Please note that not all escape sequences are supported by Discord.

Raw String Literals#

It should become relatively clear that a lot of new lines and other special characters can make a quoted string quite hard to read. To make this easier, you can use backticks (`) to create a raw string literal. A raw string literal does not attempt to interpret its contents in any way, and will simply contain the text between the opening ` and closing ` unmodified—we cannot even escape a backtick to include one in the string, but we will later cover functions that solve this special case.

`This is my
cool multiline string!

Look at all the new lines!`

Numbers#

Numeric values can be represented in two ways, using integers (whole numbers) and floating-point numbers (numbers with a decimal point). In the bot’s template actions, you can create an integer by simply writing a whole number, such as 5. For floating-point numbers, you can add a decimal point, like so: 5.0.

Integers#

In the bot’s template actions, integers are represented as 64-bit signed integers. This means that you can store numbers from -9223372036854775808 to 9223372036854775807. If you try to store a number outside this range, the bot will return an error.

The bot accepts several notations for integers:

1. As a base-10 number, such as 42. This will mean what you think, the number forty-two.
2. As a base-16 number, such as 0x2A. This is the hexadecimal representation of the number forty-two.
3. As a base-8 number, such as 0o52. This is the octal representation of the number forty-two.
4. As a base-2 number, such as 0b101010. This is the binary representation of the number forty-two.

Floating-Point Numbers#

We represent floating-point numbers as 64-bit IEEE-754 floating-point numbers. This means that you can store numbers with a precision of about 15 decimal places. If you try to store a number with more precision, the bot will round it to the nearest representable number.

There are a lot of ways to define a floating-point number, but the most common way is to use the decimal point, such as 3.14. For a full list of ways to define a floating-point number, you can refer to the Go documentation.

Booleans#

A boolean is a data type that can only have one of two values: true or false. Booleans are used to represent the truth value of an expression. For instance, 5 > 3 would evaluate to true, while 5 < 3 would evaluate to false.

You can think of it as a light switch: it can either be on (true) or off (false). Booleans are often used in conditional statements, such as if statements, to determine which branch of the code should be executed.