Odin by Example: Structs

Structs group named fields into a single type. Define a struct with the struct keyword and access fields with dot notation.

Struct literals create values. Supply all fields positionally, use named fields for partial init, or use an empty literal for the zero value.

Fields can be accessed through a pointer without explicit dereferencing: p.x works when p is ^T.

$ odin run structs.odin -file
Alice is 30 years old
Bob is 0 years old
name: Alice age: 31
point: 3, 4
zero name: true zero age: true
age after pointer: 32

package main

import "core:fmt"

Person :: struct {
	name: string,
	age:  int,
}

Point :: struct {
	x, y: int,
}

main :: proc() {
	// Struct literal with named fields.
	alice := Person{name = "Alice", age = 30}
	fmt.printf("%s is %d years old\n", alice.name, alice.age)

	// Named fields can be partial; others are zero.
	bob := Person{name = "Bob"}
	fmt.printf("%s is %d years old\n", bob.name, bob.age)

	// Modify fields after creation.
	alice.age = 31
	fmt.println("name:", alice.name, "age:", alice.age)

	// Positional literal when all fields are given.
	p := Point{3, 4}
	fmt.printf("point: %d, %d\n", p.x, p.y)

	// Zero value: empty string and zero int.
	empty := Person{}
	fmt.println("zero name:", empty.name == "", "zero age:", empty.age == 0)

	// Access fields through a pointer.
	ptr := &alice
	ptr.age = 32
	fmt.println("age after pointer:", alice.age)
}

← runes | enums →