Regex to match a word of length 10 with the first letter 'A', 5th letter 'I' and-CodePudding

I have a particular Regex requirement for a Javascript project. The Regex should match all 10 letter words starting with 'A', having it's 5th letter 'I' and the letter 'O' occuring atleast once within the word.

I'm able to match 'A' and 'I' using /A...I...../i but I'm unable to match the letter 'O' which needs to occur atleast once in the word. Any help here is appreciated.

CodePudding user response：

Instead of trying to write black magic regexes, break down the problem into simpler pieces.

const input = "...";
const tenCharactersLong = input.length === 10;
const AinFirstPosition = input[0] === "A";
const IinFifthPosition = input[4] === "I";
const atLeastOneO = input.contains("O");

If you absolutely must use a regex, then...

const blackMagic = /(?=.*O)A...I.{5}/;

... should work fine.

CodePudding user response：

This regex will find words in a text that start with an A, are 10 letters long, contain the letter O, and have an I as the 5th letter.

/\b[A](?=...I)(?=\w*O)[A-Z]{9}\b/ig

If it's just to match a complete string

/^[A](?=...I)(?=.*O)[A-Z]{9}$/i