user
Task

Create a function,   or show a built-in function,   to count the number of non-overlapping occurrences of a substring inside a string.

The function should take two arguments:

:   :   :   * the first argument being the string to search,   and
            * the second a substring to be searched for.

It should return an integer count.

```
print countSubstring("the three truths","th")
3

// do not count substrings that overlap with previously-counted substrings:
print countSubstring("ababababab","abab")
2
```

The matching should yield the highest number of non-overlapping matches.

In general, this essentially means matching from left-to-right or right-to-left   (see proof on talk page).

Other tasks related to string operations:

Metrics

* Array length
* String length
* Copy a string
* Empty string  (assignment)

Counting

* Word frequency
* Letter frequency
* Jewels and stones
* I before E except after C
* Bioinformatics/base count
* Count occurrences of a substring
* Count how many vowels and consonants occur in a string

Remove/replace

* XXXX redacted
* Conjugate a Latin verb
* Remove vowels from a string
* String interpolation (included)
* Strip block comments
* Strip comments from a string
* Strip a set of characters from a string
* Strip whitespace from a string -- top and tail
* Strip control codes and extended characters from a string

Anagrams/Derangements/shuffling

* Word wheel
* ABC problem
* Sattolo cycle
* Knuth shuffle
* Ordered words
* Superpermutation minimisation
* Textonyms (using a phone text pad)
* Anagrams
* Anagrams/Deranged anagrams
* Permutations/Derangements

Find/Search/Determine

* ABC words
* Odd words
* Word ladder
* Semordnilap
* Word search
* Wordiff  (game)
* String matching
* Tea cup rim text
* Alternade words
* Changeable words
* State name puzzle
* String comparison
* Unique characters
* Unique characters in each string
* Extract file extension
* Levenshtein distance
* Palindrome detection
* Common list elements
* Longest common suffix
* Longest common prefix
* Compare a list of strings
* Longest common substring
* Find common directory path
* Words from neighbour ones
* Change e letters to i in words
* Non-continuous subsequences
* Longest common subsequence
* Longest palindromic substrings
* Longest increasing subsequence
* Words containing "the" substring
* Sum of the digits of n is substring of n
* Determine if a string is numeric
* Determine if a string is collapsible
* Determine if a string is squeezable
* Determine if a string has all unique characters
* Determine if a string has all the same characters
* Longest substrings without repeating characters
* Find words which contains all the vowels
* Find words which contain the most consonants
* Find words which contains more than 3 vowels
* Find words whose first and last three letters are equal
* Find words with alternating vowels and consonants

Formatting

* Substring
* Rep-string
* Word wrap
* String case
* Align columns
* Literals/String
* Repeat a string
* Brace expansion
* Brace expansion using ranges
* Reverse a string
* Phrase reversals
* Comma quibbling
* Special characters
* String concatenation
* Substring/Top and tail
* Commatizing numbers
* Reverse words in a string
* Suffixation of decimal numbers
* Long literals, with continuations
* Numerical and alphabetical suffixes
* Abbreviations, easy
* Abbreviations, simple
* Abbreviations, automatic

Song lyrics/poems/Mad Libs/phrases

* Mad Libs
* Magic 8-ball
* 99 bottles of beer
* The Name Game (a song)
* The Old lady swallowed a fly
* The Twelve Days of Christmas

Tokenize

* Text between
* Tokenize a string
* Word break problem
* Tokenize a string with escaping
* Split a character string based on change of character

Sequences

* Show ASCII table
* De Bruijn sequences
* Summarize and say sequence
* Generate lower case ASCII alphabet
assistant
(formerly Perl 6)

```
sub count-substring($big, $little) { +$big.comb: / :r $little / }
 
say count-substring("the three truths", "th"); # 3
say count-substring("ababababab", "abab");     # 2
 
say count-substring(123123123, 12);            # 3
```

The :r adverb makes the regex "ratchet forward" and skip any overlapping matches. .comb - when given a Regex as an argument - returns instances of that substring. Also, prefix + forces numeric context in Raku (it's a no-op in Perl 5). For the built in listy types that is the same as calling .elems method. One other style point: we now tend to prefer hyphenated names over camelCase.