# List -- length or cardinality of a list, hash table, dictionary, set, or string

Description

i1 : L = {1, 2, 3, 2, 1};

i2 : #L

o2 = 5

i3 : S = new Set from L

o3 = set {1, 2, 3}

o3 : Set

i4 : #S

o4 = 3

i5 : T = new HashTable from {a => 1, b => 2}

o5 = HashTable{a => 1}
               b => 2

o5 : HashTable

i6 : #T

o6 = 2

i7 : s = "a perfectly adequate example of a string";

i8 : #s

o8 = 40

See also

• # -- length or access to elements
• #? -- check existence of value in a list, hash table, database, or string
• BasicList # ZZ -- get value from list, hash table, database, dictionary, or string
• keys -- keys used in a hash table, dictionary, or database
• pairs -- list the pairs in a hash table, dictionary, or basic list
• values -- values in a hash table
• hash tables
• lists and sequences -- a detailed overview of lists and sequences in Macaulay2