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The new language was created as a result of frustration with existing languages being used for personal projects.{{sfn|Chakraborty|Haldar|2023}} It was originally intended for personal use, but after being mentioned publicly and increasing interest, it was decided to make it public. V was initially created to develop a desktop messaging client named Volt.<ref name="hackaday"/> On public release, the compiler was written in V, and could [[Self-hosting (compilers)|compile itself]].{{Sfn|Rao|2021}}{{sfn|Chakraborty|Haldar|2023}} Key design goals in creating V were being easy to learn and use, higher readability, fast compiling, increased safety, efficient development, [[Cross-platform software|cross-platform]] usability, improved [[C (programming language)|C]] [[interoperability]], better [[Error detection and correction|error handling]], modern features, and more maintainable software.<ref name="MUO"/><ref name="analyticsindiamag"/><ref name="nasufi"/><ref>{{cite web |title=V language: simple like Go, small binary like Rust|url=https://techracho.bpsinc.jp/hachi8833/2021_03_09/89457/ |website=TechRacho |access-date=3 March 2021}}</ref>
 
V is released and developed through [[GitHub]],<ref>{{cite web |url=https://ossinsight.io/analyze/vlang/v#overview |title=GitHub Programming Languages (repository details) |via=[[Open-source software|OSS]] Insight using [[TiDB]] }}{{Dead link|date=July 2025 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref name="hackaday"/> and maintained by developers and contributors internationally.{{Sfn|Rao|2021}} It is among the languages that have been listed on the [[TIOBE index]].<ref>{{cite web |title=TIOBE Index |url=https://www.tiobe.com/tiobe-index |publisher=[[TIOBE index|TIOBE]]|website=tiobe |archive-url=https://web.archive.org/web/20250411043213/https://www.tiobe.com/tiobe-index/|archive-date=11 April 2025|access-date=11 April 2025}}</ref>
 
[[File:Veasel.svg|thumb|Veasel is the official mascot of the V programming language<ref>{{cite web |url=https://github.com/vlang/v-mascot/ |title=V's official mascot |website=GitHub |access-date=8 November 2023}}</ref>]]
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== Syntax ==
=== Hello world ===
The [["Hello, World!" program]] in V:<ref name="MUO"/><ref name=":0">{{Cite web |title=V Documentation |url=https://docs.vlang.io/ |access-date=2025-08-25 |website=docs.vlang.io}} {{Free-content attribution|title = V Documentation| license statement URL =https://github.com/vlang/v?tab=MIT-1-ov-file| license=The MIT License|this = yes}}</ref>
The [["Hello, World!" program]] in V:<ref name="MUO"/>
<syntaxhighlight lang="v">
fn main() {
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=== Variables ===
Variables are immutable by default and are defined using {{code|1=:=}} and a value. Use the {{code|mut}} [[reserved word]] (keyword) to make them mutable. Mutable variables can be assigned to using {{code|1==}}:{{sfn|Rao|2021|pp=28-40}}<ref name=":0" />
 
<syntaxhighlight lang="V">
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</syntaxhighlight>
 
Redeclaring a variable, whether in an inner scope or in the same scope, is not allowed:{{sfn|Rao|2021|pp=28-40}}<ref name=":0" />
 
<syntaxhighlight lang="V">
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=== Structs ===
Struct example:<ref name="Knott"/><ref name="section"/><ref name=":0" />
<syntaxhighlight lang="v">
struct FoobarFoo {
number int
name string
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// Struct fields can be initialized by name
var1 := FoobarFoo {
number: 21
name: "baz"
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// or by position
var2 := FoobarFoo{50, "quxtaz", 3.14}
</syntaxhighlight>
 
=== Heap structs ===
 
StructsBy thatdefault, structs are allocated on the [[Stack_memory|stack]]. When structs are referenced by using the prefix {{code|1=&}} or have the {{code|1=[heap]}} attribute, willthey beare allocated toon the [[Heap-based_memory_allocation|heap]] instead of the stack:{{sfn|Rao|2021}}<ref name=":0" />
<syntaxhighlight lang="v">
struct Foo {
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@[heap]
struct BarBaz {
number f32
}
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var1 := &Foo{2}
 
// BarBaz is always heap allocated because of its [heap] attribute
var2 := BarBaz{4.5}
 
</syntaxhighlight>
 
=== Methods ===
[[Method (computer programming)|Methods]] in V are functions defined with a receiver [[Parameter (computer programming)|argument]]. The receiver appears in its own argument list between the {{code|1=fn}} keyword and the method name. Methods must be in the same [[Modular programming|module]] as the receiver type.
 
The is_registeredenrolled_status method (below) has a receiver of type User{{code|1=Client}} named u{{code|1=x}}. The convention is not to use receiver names like self or this, but preferably a short name. For example:<ref name="Knott"/><ref name="nasufi"/><ref name=":0" /><syntaxhighlight lang="v">
struct UserClient {▼
 
enrolled bool
{{Copyvio|timestamp=20250715164557 |url=https://docs.vlang.io/structs.html#methods}}
<syntaxhighlight lang="V">
▲struct User {
age int
}
 
fn (ux UserClient) is_registeredenrolled_status() bool {
return x.enrolled
return u.age > 16
}
 
println(Client{enrolled: true}.enrolled_status()) // true
user := User{
println(Client{enrolled: false}.enrolled_status()) // false
age: 10
}
println(user.is_registered()) // "false"
 
user2 := User{
age: 20
}
println(user2.is_registered()) // "true"
</syntaxhighlight>
</div>
 
=== Error handling ===
Result types may represent an error returned from a function. Result types are declared by prepending {{code|!}}: {{code|!Type}}
{{Copyvio|timestamp=20250715164557 |url=https://docs.vlang.io/type-declarations.html#optionresult-types-and-error-handling}}
Optional types are for types which may represent none. Result types may represent an error returned from a function.
 
OptionOptional types are declared bymay prependingrepresent {{code|?none}}. toOption thetypes type name:prepend {{code|?Type}}. Resultto typesthe usetype {{code|!}}name: {{code|!?Type}}.<ref name="Knott"/><ref name="section"/>{{Sfn|Tsoukalos|2022}}<ref name=":0" />
<syntaxhighlight lang="V">
fn something(t string) !string {
if t == "foo" { return "foo" }
return error("invalid string")
}
 
x := something("foo") or { "default" } // x will be "foo"
y := something("carbaz") or { "default" } // y will be "default"
z := something("carbaz") or { panic("{err}") } // z will exit with an error "invalid string" and a traceback
 
println(x)
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</syntaxhighlight>
</div>
 
==See also==
Retrieved from "https://en.wikipedia.org/wiki/V_(programming_language)"