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The Above Regular Expression Question was featured on HackerRank,It should return true if string contains Mr./Mrs./Ms./Dr./Er. in the beginning followed by group of letters.

For Eg: Mr.Abc is true but Mr.Abc. isn't But my code returns Mr.Abc. as true.

let inp="Mr.Abc.";
let re=new RegExp(/^Mr\.|^Ms\.|^Mrs\.|^Dr\.|^Er\.[A-Za-z]/);
console.log(re.test(inp));

P.S.Sorry for my Bad Regular Expression statement i'm currently in the learning stage ..

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Shardul Birje
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2 Answers2

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It's a grouping problem, as well as an issue with the fact that you don't test for the end of the string using $. Using your expression, Mr.Abc. returns true because it matches ^Mr\.

Change your expression as follows:

let re = /^(Mr|Ms|Mrs|Dr|Er)\.[A-Za-z]+$/;
Robby Cornelissen
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I tried the same thing and it resolved this issue with this simple change.

let re = new RegExp(/^Mr\.|^Ms\.|^Mrs\.|^Dr\.|^Er\.[A-Za-z]*$/);

This would make the search stringent while checking the string. Hope this helps :)

ichbinpradnya
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    It might work for the specific case, but not for all cases. For example, your expression will also return true for the strings `Mr.`, `Dr.123`, and a whole lot of other cases that should not be matched. – Robby Cornelissen Dec 25 '19 at 08:00
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    Actually, this expression still matches `Mr.Abc.`, so the answer is incorrect. – Robby Cornelissen Dec 25 '19 at 08:04