Formal languages | String (computer science)
Substring
In formal language theory and computer science, a substring is a contiguous sequence of characters within a string. For instance, "the best of" is a substring of "It was the best of times". In contrast, "Itwastimes" is a subsequence of "It was the best of times", but not a substring. Prefixes and suffixes are special cases of substrings. A prefix of a string is a substring of that occurs at the beginning of ; likewise, a suffix of a string is a substring that occurs at the end of . The substrings of the string "apple" would be:"a", "ap", "app", "appl", "apple","p", "pp", "ppl", "pple","pl", "ple","l", "le""e", "" (note the empty string at the end). (Wikipedia).
