LetterCounts

LetterCounts["string"]

gives an association whose keys are the distinct letters in string, and whose values give the number of times those letters appear in string.

LetterCounts["string",n]

gives counts of the distinct n-grams consisting of runs of n letters in string.

LetterCounts["string",n,{"c1","c2",}]

allows the characters ci to appear in n-grams, in addition to ordinary letters.

Details and Options

  • LetterCounts[string,n] considers n-grams that start at every position in string and includes them in its counts if they contain only letters.
  • LetterCounts effectively uses LetterQ to determine whether to consider a character to be a letter.
  • LetterCounts has the option IgnoreCase. With the setting IgnoreCase->True, letters are in effect all converted to lower case before being counted.

Examples

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Basic Examples  (4)

Count the letters in a string:

Non-letter characters are excluded from letter counts:

Count 2-grams of letters:

Specify a list of non-letter characters to be counted:

Options  (2)

IgnoreCase  (2)

With IgnoreCase -> False, uppercase and lowercase characters will be counted independently:

Use IgnoreCase ->True to count all occurrences of a letter, regardless of case:

Count n-grams regardless of case:

Neat Examples  (1)

Find the most frequently occurring letters in a piece of text:

Do the same for 3-letter sequences:

Introduced in 2015
 (10.1)