Records in Elixir
Records in Elixir[edit]
Records in Elixir are a way to define data structures with named fields. They provide a convenient and concise way to model complex data without the need for defining explicit structs or classes. Records are similar to maps in Elixir, but with specific field names and fixed types.
Syntax[edit]
You can define a record type using the `defrecord` macro, which takes the record name as its first argument and a list of field names as its second argument. Each field name is defined atomically. Here's an example:
```elixir defmodule Person do
defrecord [:name, :age, :email]
end ```
Once a record type has been defined, you can create instances of the record using the record name as a callable function. The arguments should be given as key-value pairs, where the keys are atom field names and the values are the corresponding field values.
```elixir person = Person.new(name: "John", age: 30, email: "[email protected]") ```
Accessing Record Fields[edit]
To access a field within a record, you can use the dot notation, followed by the field name. Elixir provides a shorthand syntax for accessing record fields directly.
```elixir person.name ```
Pattern Matching with Records[edit]
Records are often used in pattern matching to destructure and manipulate data. This allows for concise and expressive pattern matching on specific fields of a record.
```elixir defmodule Greeting do
def greet(%Person{name: name}) do
IO.puts("Hello, #{name}!")
end
end ```
Updating Records[edit]
Elixir provides a convenient way to update record fields using the `|` operator. This operator allows you to create a new record that shares most of its fields with an existing record, while also modifying specific fields.
```elixir person = person|age: 31 ```
Record Comparison[edit]
By default, records are compared by value. This means that two records with identical field values will be considered equal, even if they have different object references.
Conclusion[edit]
Records in Elixir are a powerful tool for modeling complex data structures. With their named fields and pattern matching capabilities, they simplify code and make it more readable. Start using records in your Elixir projects to enhance your data modeling and manipulation capabilities!