Before introducing the basic data types of Elixir, let's briefly introduce how to identify basic functions. This will help you read the code examples later.
How to Identify functions and documentation
Functions in Elixir are identified by both their name and their arity. The arity of a function describes the number of arguments the function takes.
The Elixir shell defines the h function, which you can use to access documents for any function
h trunc/1 works because it is defined in the Kernel module.
Kernel module is Elixir's default environment.
All functions in the Kernel module are automatically imported into our namespace.
Basic types
Basic arithmetic
iex> 1 + 2
3
iex> 5 * 5
25
Operation /
The operation / always returns float instead of integer
iex > 10 / 2
5.0
Operation division or get the division's remainder
- notice that Elixir allows you to drop the parentheses when invoking functions that expect one or more arguments.
iex> div(10, 2)
5
iex> div 10, 2
5
iex> rem 10, 3
1
Elixir also supports shortcut notations for entering binary, octal, and hexadecimal numbers:
iex> 0b1010
10
iex> 0o777
iex> 511
iex> 0x1F
31
Floats in Elixir are 64-bit precision.
Float numbers require a dot followed by at least one digit and also support e for scientific notation:
iex> 1.0
1.0
iex> 1.0e-10
1.0e-10
You can invoke the round function to get the closest integer to a given float, or the trunc function to get the integer part of a float.
iex> round(4.58)
5
iex> trunc(2.58)
2
Booleans
Elixir supports true and false as booleans:
iex > true
true
iex> true === false
false
Elixir also provides three boolean operators: or/2, and/2, and not/1.
or/2 and and/2These operators are strict in that they expect something that evaluates to a boolean as their first argument.
Requires only the left operand to be a boolean since it short-circuits. If the left operand is not a boolean, a BadBooleanErrorexception is raised.
If the not/1 value is not boolean, an ArgumentError exception is raised.
iex> true or false
true
iex> false or 30
30
iex> 30 or false
** (BadBooleanError) expected a boolean on left-side of "or", got: 30
iex> true and false
false
iex> false and true
false
iex> true and "hello"
"hello"
iex> false and "hello"
false
iex> "hello" and true
** (BadBooleanError) expected a boolean on the left-side of "and", got:
"hello"
iex> not false
true
iex> not true
false
nil
Elixir also provides the concept of nil, to indicate the absence of a value and a set of logical operators that also manipulate nil: ||/2, &&/2 and !/1].
For these operators, false and nil are considered "falsy", all other values are considered "truthy".
iex> nil || true
true
iex> false || nil
nil
iex> nil || false
false
iex> nil || 1
1
iex> 1 || nil
1
iex> nil && 13
nil
iex> 13 && nil
nil
iex> nil && false
nil
iex> false && nil
false
iex> !nil
true
Atoms
An atom is a constant whose value is its name. Some other languages call these symbols.
They are often useful to enumerate over distinct values Often they are used to express the state of an operation, by using values such as :ok and :error.
Atoms are equal if their names are equal and Elixir allows you to skip the leading : for the atoms false, true, and nil.
iex> :apple
:apple
iex> :banana
:banana
iex> :apple ==:apple
true
iex> :apple == :banana
false
iex> true == :true
true
iex> is_atom(false)
true
iex> is_atom(:false)
true
String
Strings in Elixir are UTF-8 encoded binaries.
It is a sequence of Unicode characters, typically written between double quoted strings, such as "hello" and "héllò".
And you can use the binary concatenation operator <>/2. Concatenates two binaries.
If one of the sides isn't binaries, will raise an ArgumentError
iex> "hello"
hello
iex> "hello" <> "world"
"helloworld"
iex> "hello " <> "world"
"hello world"
iex(1)> "foo" <> x = "foobar"
"foobar"
iex(2)> x
"bar"
iex> x <> "bar" = "foobar"
(ArgumentError) cannot perform prefix match because the left operand of <> has an unknown size
Elixir supports string interpolation on both sides and supports any data type that may be converted to a string and can have line breaks in them using escape
iex(1)> string = "world"
iex(2)> "hello #{string}!"
"hello world!"
iex(1)> string = "Hello"
iex(2)> "#{string} world!"
"Hello world!"
iex(1)> number = 24
iex(2)> "i am #{number} years old!"
"i am 24 years old!"
iex(1)> "hello
...(1)> world"
"hello\nworld"
iex> "hello\nworld"
"helo\nworld"
You can use IO.puts/1.
This function is from the IO module, the IO function handling input/output (IO).
Notice that the IO.puts/1 function returns the atom :ok after printing.
iex> IO.pust("hello\nword")
hello
world
:ok
Strings in Elixir are represented internally by contiguous sequences of bytes known as binaries and we can get the number of bytes a string
iex> is_binary("hello")
true
iex> is_binary("hellö")
true
iex> byte_size("hello")
5
iex> byte_size("hellö")
6
- Notice that the number of bytes in that string is 6, even though it has 5 graphemes. That's because the grapheme "ö" takes 2 bytes to be represented in UTF-8.
We can get the actual length of the string, based on the number of graphemes, by using the
String.length/1function will return the number of Unicode graphemes in a UTF-8 string.
iex> String.length("hello")
5
iex> String.length("hellö")
5
iex> String.length("涼涼")
2
The [String]module contains a bunch of functions that operate on strings as defined in the Unicode standard like downcase/2 and upcase/2.
The downcase/2 gives string to lowercase according to mode and upcase/2 gives string to uppercase according to mode.
iex> String.downcase("ABCD")
"abcd"
iex> String.downcase("AB 123 XPTO")
"ab 123 xpto"
iex> String.downcase("OLÁ")
"olá"
iex> String.upcase("abcd")
"ABCD"
iex> String.upcase("ab 123 xpto")
"AB 123 XPTO"
iex> String.upcase("olá")
"OLÁ"
Predicate function
We work with different data types, we will learn Elixir provides several predicate functions to check for the type of a value.
For example, the is_integer can be used to check if a value is an integer or not.
If you want to know other the predicate functions you can check the below link 👇
Other the predicate functions
is_integer(1)
true
is_integer(2.0)
false
Structural comparison
Elixir also provides ==, !=, <=, >=, < and > as comparison operators. We can compare numbers but also atoms, string, and booleans can do.
Integers and floats compare the same if they have the same value but if you use the strict comparison operator === and !== if you want to distinguish between integers and floats they are different.
iex> 1 == 1
true
iex> 1 != 2
true
iex> 1 < 2
true
iex> "foo" == "foo"
true
iex> "foo" == "bar"
false
iex> 1 == 1.0
true
iex> 1 == 2.0
false
iex> 1 === 1.0
false
The comparison operators in Elixir can compare across any data type. We say these operators perform structural comparison.
For more information, you can click below link 👇
Structural vs Semantic comparisons.
Other tips
Elixir also supports shortcut notations for entering binary, octal, and hexadecimal numbers:
iex> 0b1010
10
iex> 0o777
511
iex> 0x1F
31
Float numbers require a dot followed by at least one digit and also support e for scientific notation:
iex> 1.0
1.0
iex> 1.0e-10
1.0e-10
This wraps up today's introduction to basic data types. If you haven't read the previous article, How to get start Elixir, go give it a read. Our next article will delve into lists and tuples as data types. Make sure not to miss it. See you next time, bye!
Top comments (1)
This is the second article in my Elixir journal series.
Everyone is welcome to learn with me. 😊