String Matching The string matching problem is the following: Given a text string T and a nonempty string P, find all occurrences of P in T. (Why must P be nonempty?) T is typically called the pattern.

ng Functionality To retrieve an element of a string, just use [], exac. ly like vectors. In addition, you can iterate through a string ju. t like a vector. The following function, for example, returns the first index of …

Introduction Sequence of zero or more characters, terminated by NUL (literally, the integer value 0) Every string is terminated by NUL and NUL is not part of the string.

The stringstrings package provides a large and sundry array of routines for the manipulation of strings.

Exercise: Assuming the string world sheet to be timelike, check that we can impose the boundary condition (3.4) on any closed string, while keeping the coordinate condition

Pattern arguments in stringr are interpreted as regular expressions after any special characters have been parsed. In R, you write regular expressions as strings, sequences of characters surrounded by …

These notes are based on the string theory lecture course by Prof. Amihay Hanany, taught at Imperial College London in 2025. While they broadly follow the structure of the course, at times I decided to …