StringTake¶

$ wo 'StringTake["Hello World!", 5]'
Hello

A span i;;j takes characters i through j.

$ wo 'StringTake["hello", 2;;4]'
ell

$ wo 'StringTake["hello", ;;-2]'
hell

A three-element specification {m, n, s} is a span with step s:

$ wo 'StringTake["abcde", {1, 5, 2}]'
ace

A list of integers that cannot be read as a span is re-read as a list of separate specifications, one result per entry. A step of 0 makes the span reading impossible, so {1, 5, 0} means "take 1, take 5, take 0":

$ wo 'StringTake["abcde", {1, 5, 0}]'
{a, abcde, }

Four or more entries can never be a span, so they are always read that way:

$ wo 'StringTake["abcde", {1, 2, 3, 4}]'

StringTake::ambgsntx: Warning: interpreting list of integers as a list of sequence specifications.
{a, ab, abc, abcd}

An empty specification takes nothing:

$ wo 'StringTake["abcde", {}]'