VisibleList _ ZZ -- get element from list

Synopsis

• Operator: _

• Usage:

  x_i

• Inputs:
  • x, a visible list
  • i, an integer
• Outputs:
  • the i-th element of the list x

Description

The entries of the list, sequence or array are numbered starting with 0. If i is negative, then the i-th entry counting from the end is provided. If i is out of range, an error is signaled.

i1 : x = a..t

o1 = (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t)

o1 : Sequence

i2 : #x

o2 = 20

i3 : x_-1, x_19, x_0

o3 = (t, t, a)

o3 : Sequence

Caveat

See also

• BasicList # ZZ -- get value from list, hash table, database, or string