Go Structs: Difference between revisions

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=Fields=
=Fields=


Fields can be access with the <tt>.</tt> operator.
Fields can be access with the <tt>[[Go_Concepts_-_Operators#.|.]]</tt> operator.


<font color=red>A field is always [[Go Concepts - Packages#Exported_Identifiers|exported]] by the package it is enclosed in.</font>
<font color=red>A field is always [[Go Concepts - Packages#Exported_Identifiers|exported]] by the package it is enclosed in.</font>

Revision as of 03:01, 30 March 2016

Internal

Overview

A struct is a user-defined type that contains named fields.

Are all users can define (in terms of types) structs, or there are other user-defined types?

Definition

The struct type definition is introduced by the type keyword, to indicated that this is a user-defined type, followed by the type name and the keyword struct. Each field has a name and a type.

type myStruct struct {
    i int
    s string
}

Fields with the same types can be collapsed:

type myStruct struct {
    ...
    i, j, k int
   ...
}

Initialization

Long Variable Declaration

var ms myStruct

If no explicit initialization follows, all the struct's fields are initialized with their zero value.

Short Variable Declaration

Literal

Struct literal initialization:

ms := myStruct{i: 5, s: "something"}

There is a shorter struct literal where the name of the fields are omitted, provided that the order is maintained:

ms := myStruct{5, "something"}

new()

new() initialization:

msPtr := new(myStruct)

Note new() returns a pointer to the structure and not the structure itself.

Fields

Fields can be access with the . operator.

A field is always exported by the package it is enclosed in.