CODEWITHSUNDEEP
javascriptregex
Howard
Howard

Reputation: 151

What is the regex to match alphanumeric 6 character words, separated by space or comma

I am newbie in RegEx and trying to design a RegEx which could match the String like below:

pattern 1 separated by comma and a space: KEPM39, JEMGH5, HEPM21 ... (repeat)

pattern 2 separated only by a space: KEPM39 JEMGH5 HEPM21 ... (repeat)

pattern 3 separated only by a comma: KEPM39,JEMGH5,HEPM21 ... (repeat)

this is my concept: "^[a-zA-Z0-9]{6,}[,\s]+$" but it seems wrong.

#I want to validate the whole string, and I use javascript & html to validate user input. (textarea)

#duplicate change to repeat to be more suitable.

function validate(){
    var term = "JEPM34, KEPM11 ";
    var re = new RegExp("^[a-zA-Z0-9]{6,}[,\s]+$");
    if (re.test(term)) {
        return true
    } else {
        return false
    }
}

thanks you in advance!

Upvotes: 0

Views: 405

Answers (2)

The fourth bird
The fourth bird

Reputation: 163467

If you want consistent delimiters, and there can be trailing spaces (as there is in your example data) you can use a capture group with a backreference \1 to keep consistent delimiters and match optional spaces at the end.

Note that you can also use \s but that could also match a newline.

Using test will return a boolean, so you don't have to use return true or false but you can return the result test`

^[A-Z\d]{6}(?:(, ?| )(?:[A-Z\d]{6}\1)*[A-Z\d]{6} *)?$

The pattern matches:

  • ^ Start of string
  • [A-Z\d]{6} Match 6 occurrences of a char A-Z or a digit
  • (?: Non capture group to match as a whole
    • (, ?| ) Capture group 1, match either a comma and optional space, or a space to be used as a backreference
    • (?:[A-Z\d]{6}\1)* Optionally repeat any of the listed followed by a backreference \1 to group 1 which will match the same delimiter
    • [A-Z\d]{6} * Match any of the listed and optional spaces at the end
  • )? Close the group and make it optional to also match an instance without delimiters
  • $ End of string

Regex demo

const regex = /^[A-Z\d]{6}(?:(, ?| )(?:[A-Z\d]{6}\1)*[A-Z\d]{6} *)?$/;
const validate = term => regex.test(term);

[
  "KEPM39, JEMGH5, HEPM21",
  "KEPM39 JEMGH5 HEPM21",
  "KEPM39,JEMGH5,HEPM21",
  "JEPM34, KEPM11 ",
  "JEPM34, KEPM11",
  "JEPM34",
  "KEPM39, JEMGH5 HEPM21, HEGD44    ZZZZZZ",
  "KEPM39, JEMGH5 HEPM21"
].forEach(s =>
  console.log(`${s} ==> ${validate(s)}`)
);

Upvotes: 2

JvdV
JvdV

Reputation: 75910

A very loose way to validate could be:

^[A-Z\d]{6}(?:[ ,]+[A-Z\d]{6})*$

See the online demo. With loose, I meant that [ ,]+ is not checking that each delimiter in your string is the same per definition. Therefor even "KEPM39, JEMGH5 HEPM21, HEGD44 ZZZZZZ" would be valid.

Upvotes: 3

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