The NGrams( s, n ) command computes the ordered list of n-grams of the string s. The second argument n must be a 32-bit positive integer no larger than the length of s.

An n-gram of s is a substring of s consisting of exactly n contiguous characters from s.

The empty string $''''$ has no n-grams, for any value of n.

Note that NGrams( s, 1 ) is equivalent to $\mathrm{Explode}\left(s\right)$.

All of the StringTools package commands treat strings as (null-terminated) sequences of $8$-bit (ASCII) characters.  Thus, there is no support for multibyte character encodings, such as unicode encodings.

$\mathrm{with}\left(\mathrm{StringTools}\right)\:$

$\mathrm{NGrams}\left(''abcd''\,1\right)$

$\left[''a''\,''b''\,''c''\,''d''\right]$

$\mathrm{NGrams}\left(''abcd''\,2\right)$

$\left[''ab''\,''bc''\,''cd''\right]$

$\mathrm{NGrams}\left(''abcd''\,3\right)$

$\left[''abc''\,''bcd''\right]$

$\mathrm{NGrams}\left(''abcd''\,4\right)$

$\left[''abcd''\right]$

$\mathrm{NGrams}\left(''mathematics''\,3\right)$

$\left[''mat''\,''ath''\,''the''\,''hem''\,''ema''\,''mat''\,''ati''\,''tic''\,''ics''\right]$