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Strings
In V one can define strings using the
:= operator. Strings (like other variables) are immutable by default. One is free to use "" or '' to denote a string. When using vfmt all double-quoted strings will be converted to single-quoted ones unless it contains a single quote character.1
name := 'Bob'
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println(name) // Bob
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println(name.len) // 3
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Getting the length of a string works with
.len.Interpolation
It is possible to do string interpolation with
$ in front of the variable:1
name := 'Bob'
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println('Hello $name!') // Hello Bob!
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One can have more complex expressions with interpolation syntax by using
${}:1
struct User {
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name string
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age int
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}
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bob := User {
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name: 'Bob'
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age: 17
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}
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println('Say Hello to a new User: ${bob.name}, ${bob.age}') // Say Hello to new User: Bob, 17
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println('${bob.name}s age is higher or equal to 18: ${bob.age >= 18}') // 0 <=> number representation for false
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Concatenation
Strings can be concatenated with the
+ operator.1
text := 'Hello'
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concatenated_text := text + ' World!'
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println(text) // Hello
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println(text + ' World!') // Hello World!
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println(concatenated_text) // Hello World!
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Appending to a string works with concatenation as well as with
+= operator. Since strings are immutable by default it is only possible to do this if they are declared with mut.1
mut hello := 'Hello '
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hello += 'from V!' // appends 'from V!' to the string stored in hello.
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println(hello) // Hello from V!
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In V, string data is encoded using UTF-8 and the string itself is a read-only array of bytes. This makes slicing possible, which means we can access single-character literals or slices of a string variable.
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robert := 'Robert'
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bert := robert[2..robert.len] // bert
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rob := robert[0..3] // Rob
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println('The persons of interest are: $robert, $bert, $rob') // The persons of interest are: Robert, bert, Rob
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Notes
When using
some_string[start..end] syntax the end is not inclusive.All operators in V must have values of the same type on both sides. The code below will not compile because
age is an int:1
age := 25
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println('age = ' + age)
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We therefore need to convert it to string by using
.str() or use string interpolation (preferred):1
age := 25
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println('age = ' + age.str()) // age = 25
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println('age = $age') // age = 25
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To define character literals use:
`` . Raw strings can be defined as prepending r. They are not escaped.1
hello := 'Hello\nWorld'
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println(hello) // Hello
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// World
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raw_hello := r'Hello\nWorld'
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println(raw_hello) // Hello\nWorld
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Last modified 1yr ago
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