Count

count returns how many things are in a string or collection.

Overview

Use count when you want the size of a value:

names | ["daniel", "dave", "amanda", "frank"]

:count(names)  /// 4

names | ["daniel", "dave", "amanda", "frank"]

:count(names)  /// 4

For size, count is the same thing as len:

x | [1, 2, 3, 4, 5]

:count(x)  /// 5
:len(x)    /// 5

x | [1, 2, 3, 4, 5]

:count(x)  /// 5
:len(x)    /// 5

Dot style is also available:

x.count   /// 5
x.len     /// 5
x.length  /// 5

x.count   /// 5
x.len     /// 5
x.length  /// 5

Call Styles

The primary form is the builtin call:

:count(names)

:count(names)

Dot style is a shorthand:

names.count
names.count()

names.count
names.count()

For length-only checks, these are equivalent:

:count(names)
:len(names)
:length(names)

names.count
names.len
names.length

:count(names)
:len(names)
:length(names)

names.count
names.len
names.length

Arrays

For arrays, count returns the number of elements:

scores | [10, 20, 30]

:count(scores)  /// 3

scores | [10, 20, 30]

:count(scores)  /// 3

Nested arrays count as one element each:

rows | [[1, 2], [3, 4]]

:count(rows)  /// 2

rows | [[1, 2], [3, 4]]

:count(rows)  /// 2

Strings

For strings, count returns the number of characters:

name | "Goblin"

:count(name)  /// 6

name | "Goblin"

:count(name)  /// 6

This counts characters, not bytes:

word | "café"

:count(word)  /// 4

word | "café"

:count(word)  /// 4

Maps

For maps, count returns the number of entries:

person | {name: "Mina", role: "Archivist"}

:count(person)  /// 2

person | {name: "Mina", role: "Archivist"}

:count(person)  /// 2

It counts keys, not nested values.

Nil and Unit

:count(nil) returns 0:

:count(nil)  /// 0

:count(nil)  /// 0

Dot style also treats nil.count, nil.len, and nil.length as 0:

missing | nil

:count(missing)  /// 0

missing.count    /// 0
missing.len      /// 0

missing | nil

:count(missing)  /// 0

missing.count    /// 0
missing.len      /// 0

Counting Substrings

With two string arguments, count counts non-overlapping occurrences of a substring:

spell | "abracadabra"

:count(spell, "abra")  /// 2

spell | "abracadabra"

:count(spell, "abra")  /// 2

Dot style works too:

spell.count("a")  /// 5

spell.count("a")  /// 5

An empty substring returns 0:

:count("Goblin", "")  /// 0

:count("Goblin", "")  /// 0

Use Count Matching when you want to count regex matches.

Count vs Len

The builtin form is the main form:

if :count(cart) > 0
    checkout_enabled | true
end

if :count(cart) > 0
    checkout_enabled | true
end

if :len(password) < 12
    password_ok | false
end

if :len(password) < 12
    password_ok | false
end

Dot style is available when it reads better inside a chain or a quick check:

if cart.count > 0
    checkout_enabled | true
end

if cart.count > 0
    checkout_enabled | true
end

count feels natural for collections. len feels natural for strings. In Goblin, they answer the same length question.

Signature

:count(value)
value.count
value.count()

:len(value)
value.len
value.length

:count(text, substring)
text.count(substring)

:count(value)
value.count
value.count()

:len(value)
value.len
value.length

:count(text, substring)
text.count(substring)

Returns an integer.

Errors

count accepts one argument for size, or two string arguments for substring counting:

:count()
/// error: R0301 wrong-arity

:count("Goblin", "o", "extra")
/// error: R0301 wrong-arity

:count()
/// error: R0301 wrong-arity

:count("Goblin", "o", "extra")
/// error: R0301 wrong-arity

Unsupported values raise a type error:

:count(42)
/// error: T0205 type-mismatch

:count(42)
/// error: T0205 type-mismatch

Substring counting requires both arguments to be strings:

:count("Goblin", 1)
/// error: T0205 type-mismatch

:count("Goblin", 1)
/// error: T0205 type-mismatch