= Struct Initialization =

''Part of'' TutorialFundamentals

== Description ==

Shows different ways of initializing struct types.

== Example ==

{{{
#!d
import std.stdio;

struct Foo
{
    int a;
    int b;
    int c;
}

void main()
{
    /* #1 */
    Foo foo1 = Foo();        
    
    /* #2 */
    Foo foo2 = Foo(1, 2);
    
    /* #3 */
    static Foo foo3 = { c: 3, b: 2, a: 1 };

    /* #4 */
    Foo foo4 = { 1, 2, 3 };     

    /* #5: Arrays of Foo structs */
    Foo[] foo5 = [Foo(), Foo()];
    
    Foo[] foo6 = [Foo(1, 2), Foo(3, 4, 5)];
    
    static Foo[] foo7 = [{ a: 1, b: 2, c: 3 }, { c: 4, b: 5, a: 6 }];
    
    Foo[] foo8 = [{ 1, 2, 3 }, { 4, 5, 6 }];
}
}}}

== Explanation ==

1: Calling a structure type with empty parantheses ( '''structType()''' ) constructs a struct with all of its fields initialized to their type's .init property.

2: Calling a structure type with arguments will initialize the struct's fields in the order of the field declarations. In this case '''foo2.a''' is initialized to '''1''', '''foo2.b''' to '''2'''. Notice that you don't have to provide all of the arguments, '''foo3.b''' will be initialized to '''int.init''', which is '''0'''. 

3: This is the static initializer syntax, used for initializing static variables.

4: This is another form of the static initializer syntax. However, if explicit field names are '''not''' used, then this syntax may be used to initialize non-static variables.

5 and onwards: Initializing an '''array of Foo structs''' is conceptually the same as initializing a single Foo struct. The difference is that you have to use the ''array literal'' syntax. This enables you to provide multiple struct initializers, with the simple convention of the syntax '''[ init1, init2, initN ]'''. 

== More Information ==


More information on the usage of struct initializers can be found in the [http://www.digitalmars.com/d/2.0/struct.html Phobos documentation].