Regular Expression: first character alphabet second onward numeric

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This is my string, which always starts with a alphabet followed by 3 digits, then - (hyphen), followed by 3 digits, then alphabet, then 4 digits


I have come up with a regular expression, which seems to be very long! How can I write a better expression for this?

[a-zA-Z][0-9][0-9][0-9][-][0-9][0-9][0-9][a-zA-Z].........goes on


  • Shall support case insensitive
  • Hyphen, S and N always constant

Try this:

var testString = "I123-123S1234N1234";
var pattern = @"[A-Za-z]\d{3}-\d{3}[sS]\d{4}[nN]\d{4}";
var isMatch = Regex.Match(testString, pattern).Success;

Pattern used: [A-Za-z]\d{3}-\d{3}[sS]\d{4}[nN]\d{4}


[A-Za-z] - match any letter

\d{3} - match three digits

[sS] - match S or s literally

\d{4} - match four digits

[nN] - match N or n literally

\d{4} - match four digits

Regex to check if first 2 characters in a string are Alphabets, Not familiar with actionscript, but if it follows normal regex type rules, you need a regex more like: /^[A-Za-z]{2}/. to match two alpha characters at the start of a� We also call these regular expressions as T-SQL RegEx functions. In this article, we will use the term T-SQL RegEx functions for regular expressions. We can have multiple types of regular expressions: Alphabetic RegEx Numeric RegEx Case Sensitivity RegEx Special Characters RegEx RegEx to Exclude Characters Pre-requisite

First use the case-insensitive flag, and then when repeating tokens, use {<number of times to repeat>}` instead of repeating yourself:


If you want to match the trailing N1234 as well, then put the final [a-z][0-9]{4} in a group, and repeat it twice:


If the S and N are constant, then don't use character sets to match them, just match the plain characters:


Regular Expression (Regex) Tutorial, To match a character having special meaning in regex, you need to use a escape range, e.g., [0-9] matches any digit; [A-Za-z] matches any uppercase or lowercase letters. replaceFirst(), which replaces the first match String replacementStr = "**" In Perl (and JavaScript), a regex is delimited by a pair of forward slashes� More complex expressions are built up using meta-characters that have special meanings in regular expressions. Many punctuation characters are regular expression meta-characters. Paul Murrell’s Introduction to Data Technologies provides a good introduction in Section 9.9.2 and an extensive reference in Chapter 11. The Strings chapter in R for

if you are sure to have capital letter and S and N constant:


[A-Z] - match any uppercase letter

\d{3} - match 3 digits

S - match S literally

\d{4} - match 4 digits

N - match N literally

\d{4} - match 4 digits

if you want upper and lower case:




Starting letter to be alphabet using validation rule, Starting letter to be alphabet using validation rule field the first letter it should be allowed letter not the numbers or special characters /regular-expression- related-first-character-alphabet-second-onwards-alphanumeric. When using the dash to define a range of characters, the first character must precede the second character in alphabetic or numeric order. For example, "[0-9]" is valid, but "[9-0]" is not valid. The parentheses are used to group characters.

This should work:


First Character Letter, Second Character Any Latin Non , Toggle navigation. RegEx Pal From Dan's Tools. Web Dev. HTML/JS/CSS Playground � HTML Color Codes � CSS Fonts � Online Diff Tool .htaccess Generator� A regular expression (sometimes called a rational expression) is a sequence of characters that define a search pattern, mainly for use in pattern matching with strings, or string matching, i.e. “find and replace”-like operations.(Wikipedia). Regular expressions are a generalized way to match patterns with sequences of characters.

JavaScript Regex for first character alphabet only, second and , I need help in regex where first character alphabet only, second and onwards a non-whitespace character \S and update the quantifier to reflect the numbers� In the final section, we’ll look at other special characters, the not symbol with regular expressions, and applying some of these in business situations. Additional Information Using the above techniques, write a regular expression query that looks for 3 first characters of any digit 0 through 9, followed by two alphabetic characters E

Regular Expressions Quick Start, The most basic regular expression consists of a single literal character, such as a . It matches the first occurrence of that character in the string. This regex can match the second a too. In a text editor, you can do so by using its “Find Next” or “Search Forward” [0-9a-fxA-FX] matches a hexadecimal digit or the letter X. "string argument" - The default depends on the content of the very first search string. (Remember that <space> is used to delimit search strings.) If the first search string is a valid regular expression that contains at least one un-escaped meta-character, then all search strings are treated as regular expressions.

Using Regex for Text Manipulation in Python, Similarly, you may want to extract numbers from a text string. Writing The first parameter of the match function is the regex expression that you want to search. The pattern should be enclosed in single or double quotes like any other string. The match function can be used to find any alphabet letters within a string. A string is said to match a regular expression if it is a member of the regular set described by the regular expression. As with LIKE , pattern characters match string characters exactly unless they are special characters in the regular expression language — but regular expressions use different special characters than LIKE does.

  • If it's always that fixed format, I think I would split it up using substring rather than regex.
  • @HansKilian Is Regex expensive operation?
  • Substring is just easier to code and read, I think.
  • will mark as answer! But it shall support for small letters too! [a-z]
  • There is a regex option that makes it case insensitive, thus making it more simple.
  • @bradbury9 Yes, you are right, but I prefer using flags only when needed badly
  • \d is also a lot shorter than [0-9]
  • @fubo It does with case insensitive flag. Which he mentions to use.
  • what is (?i) here
  • @bdebaere Better to avoid \d when you don't want to possibly match other numeric characters - it's nice to be as specific as possible
  • @kudlatiger (?i) is the case-insensitive flag