Regular expression to grab all single letters before a period

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I'm trying to come up with a regex expression to grab all single letters before a period.

For example in the following sentence :

a. Lorem ipsum dolor sit amet, consectetur adipiscing elit, d. Donec euismod magna velit, ac tincidunt nisl faucibus eu

The regex should grab a and d.

Using

/^([^.]+)/

I'm able to capture the first a, but not the subsequent d.

If I understood you well, you asking for a lookahead and the 'g' modifier:

console.log(
    "a. Lorem bla bla bla d. Donec euismod,,,"
        .match(/[^.](?=\.)/g)
);
// [ 'a', 'd' ]

The g modifier is what tells regular expression engine to fetch all matches instead of only first one.

The (?=\.) is a lookahead assertion claiming (but not matching) for a '.' just after the previous assertion.

Special pattern matching character operators, Match any character (except newline) $ Match the end of the line (or before for any single character to match where a . is placed in a regular expression. [0-9]% a string that has a character from 0 to 9 before a % sign [^a-zA-Z] a string that has not a letter from a to z or from A to Z. In this case the ^ is used as negation of the expression

For ASCII alphabets demo:

/([a-z])\./mgi

For Unicode characters demo:

/(\p{L})\./mg

Regex to Test The Same Part of The String for More Than One , With lookaround, you can have a regular expression test the same part of the to find any word between 6 and 12 letters long containing either “cat”, “dog” or that in a successful match, there can never be more than 3 letters before “cat”. the regex engine to try matching “cat” at the last two letters, at the last single letter ,� Url Validation Regex | Regular Expression - Taha Match or Validate phone number nginx test Match html tag Blocking site with unblocked games Find Substring within a string that begins and ends with paranthesis Empty String Checks the length of number and not starts with 0 Match dates (M/D/YY, M/D/YYY, MM/DD/YY, MM/DD/YYYY) 10-digit phone number

You can try with positive look-ahead to to grab all single letters before a period. SEE REGEX

[a-zA-Z](?=\.)

1.4. Regular Expressions, [^abc] means "begins with any character but a,b,c", e.g. query [^aeou]ang will match "rang" but not "baang". [a-zA-Z] means "a charater from a/A through z/Z", e.g.� (dot) metacharacter, and can match any single character (letter, digit, whitespace, everything). You may notice that this actually overrides the matching of the period character, so in order to specifically match a period, you need to escape the dot by using a slash \. accordingly.

[PDF] Regular Expressions: The Complete Tutorial, The most basic regular expression consists of a single literal character, e.g.: Escaping a single metacharacter with a backslash works in all regular expression flavors. In regular expressions, the dot or period is one of the most commonly used Because “start of string” must be matched before the match of �\d+�, and. You see, there is a problem with the above pattern: all the parts are optional, that is, each part can match a null string - no sign, no digits before the period, no period, no digits after the period.

Simple RegEx Tutorial, First of all, let's take a look at two special symbols: '^' and '$'. "^abc$". a string that starts and ends with "abc" - effectively an exact match comparison. "notice". Regular expression: Surprise!* Matches: Surprise, Surprise!, Surprise!!, Surprise!!!, and so on. If the "*" notation is combined with the wildcard (period) character, it will match all (zero or more) characters, including spaces, tabs and line breaks between two separate notations: Regular expression: Hello.*There!

Replace text using regular expression, This MATLAB function replaces the text in str that matches expression with The regular expression matches single characters ( . ) that follow the beginning of the character vector (^) or a period (\.) Possessive expression: match as much as possible, but do not rescan any portions of the text. Introduced before R2006a. 6.2.1. Regular Expression Syntax¶. A regular expression (or RE) specifies a set of strings that matches it; the functions in this module let you check if a particular string matches a given regular expression (or if a given regular expression matches a particular string, which comes down to the same thing).

Comments
  • Try ([^,.]+)\., see this demo. Or [^,.]+(?=\.) (demo).
  • Your current regex matches a sequence of characters other than dot from the beginning of a string, which explains why it matches the a from your string but nothing else. ^ represents the beginning of a string, (...) is a capturing group and could likely be ommited in this context, [...] is a character class and [^...] in particular define negated character class which match anything but the characters it contains (anything but . here), and + is a quantifier which defines that the previous token (the character class) should be matched at least 1 time and as many times as possible