CODEWITHSUNDEEP
javascriptregex
F. Vosnim
F. Vosnim

Reputation: 574

Regex exclude characters at start and end

I'm trying to select all [a-z',] symbols but exclude commas at start and end. Keep only the selection inside the red rect. How can I do this? enter image description here

Upvotes: 1

Views: 1106

Answers (3)

JvdV
JvdV

Reputation: 75850

I think what you want is an optional capturing group repeating zero or more times:

[a-z](?:[',]*[a-z]+)*

See the Online Demo

  • [a-z] - A character in the range a-z.
  • (?: - Open non-capturing group.
    • [',]* - Zero or more characters from the specified character class.
    • [a-z]+ - At least one character in the range a-z.
    • )* - Close non-capturing group and match it zero or more times.

enter image description here

Note: If for good reasons OP's intention was to match a quote at the very end, we can add an optional apostrophe: [a-z](?:[',]*[a-z]+'?)*. See an online demo

Upvotes: 3

Cary Swoveland
Cary Swoveland

Reputation: 110675

You could match with the following regular expression.

[a-z'](?:[a-z',]*[a-z'])?

Start your engine!

Javascript's regex engine performs the following operations.

[a-z']      : match one character in character class
(?:         : begin non-capture group
  [a-z',]*  : match 0+ characters in character class
  [a-z']    : match one character in character class
)           : end non-capture group
?           : optionally match non-capture group

Upvotes: 1

Jan
Jan

Reputation: 43169

You could first replace the commas in question and select the characters you want afterwards:

let string = `,,."?!tats,t'ats,t,s',l,f,%$,`;

string = string.replace(/^,|,$/g, "~ooo~");
console.log(string);

In other languages you could use lookarounds (a negative lookbehind and a positive lookahead, that is).

Upvotes: 1

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