Searching with Regular Expressions (RegEx) A regular expression is a form of advanced searching that looks for specific patterns, as opposed to certain terms and phrases. With RegEx you can use pattern matching to search for particular strings of characters rather. This set of Compilers Multiple Choice Questions & Answers (MCQs) focuses on “Finite Automata and Regular Expressions”. Number of states of FSM required to simulate behaviour of a computer with a memory capable of storing “m” words, each of length ‘n’ a) m x 2n b) 2mn c) 2(m+n) d) All of the mentioned.
Practice Problems
Expressions 1 2 1 – Play With Regular Expressions LikeProblem 1: Matching a decimal numbersProblem 2: Matching phone numbersProblem 3: Matching emailsProblem 4: Matching HTMLProblem 5: Matching specific filenamesProblem 6: Trimming whitespace from start and end of lineProblem 7: Extracting information from a log fileProblem 8: Parsing and extracting data from a URLProblem X: Infinity and beyond!
Characters include normal letters, but digits as well. In fact, numbers 0-9 are also just characters and if you look at an ASCII table, they are listed sequentially.
Over the various lessons, you will be introduced to a number of special metacharacters used in regular expressions that can be used to match a specific type of character. In this case, the character d can be used in place of any digit from 0 to 9. The preceding slash distinguishes it from the simple d character and indicates that it is a metacharacter.
Below are a few more lines of text containing digits. https://daddydatnow.weebly.com/free-tennis-ladder-template-free-software.html. Try writing a pattern that matches all the digits in the strings below, and notice how your pattern matches anywhere within the string, not just starting at the first character. We will learn how to control this in a later lesson.
Expressions 1 2 1 – Play With Regular Expressions Worksheets
Solve the above task to continue on to the next problem, or read the .
Next – Lesson 2: The Dot
Previous – Lesson 1: An Introduction, and the ABCs
Find RegexOne useful? Please consider
to support our site.
Comments are closed.
|
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |