1. In computer programming, a string is traditionally a sequence of characters, either as a literal constant or as some kind of variable. The latter may allow its elements to be mutated and the length changed, or it may be fixed (after creation). A string is generally understood as a data type and is often implemented as an array data structure of bytes (or words) that stores a sequence of elements, typically characters, using some character encoding. A string may also denote more general arrays or other sequence (or list) data types and structures.
2. In computer science a string is any finite sequence of characters.An important characteristic of each string is its length, which is the number of characters in it. The length can be any natural number. A particularly useful string for some programming applications is the empty string, which is a string containing no characters and thus having a length of zero. A substring is any contiguous sequence of characters in a string.
https://en.wikipedia.org/wiki/String_(computer_science) (1.); http://www.linfo.org/string.html (2.)
Author: Anja Muskowitz