Day 7: Regular Expressions II :- 10 Days Of JavaScript HackerRank Solutionj

Problem:-

Task

Complete the function in the editor below by returning a RegExp object, , that matches any string  satisfying both of the following conditions:

• String  starts with the prefix Mr., Mrs., Ms., Dr., or Er.
• The remainder of string  (i.e., the rest of the string after the prefix) consists of one or more upper and/or lowercase English alphabetic letters (i.e., [a-z] and [A-Z]).

Constraints

• The length of string  is  .

Output Format

The function must return a RegExp object that matches any string  satisfying both of the given conditions.

Sample Input 0

Mr.X

Sample Output 0

true

Explanation 0

This string starts with Mr., followed by an English alphabetic letter (X).

Sample Input 1

Mrs.Y

Sample Output 1

true

Explanation 1

This string starts with Mrs., followed by an English alphabetic letter (Y).

Sample Input 2

Dr#Joseph

Sample Output 2

false

Explanation 2

This string starts with Dr# instead of Dr., so it's invalid.

Sample Input 3

Er .Abc

Sample Output 3

false

Explanation 3

This string starts with Er but there is a space before the period (.), making the string invalid.

Solution:-

'use strict';

process.stdin.resume();

process.stdin.setEncoding('utf-8');

let inputString = '';

let currentLine = 0;

process.stdin.on('data', inputStdin => {

inputString += inputStdin;

});

process.stdin.on('end', _ => {

inputString = inputString.trim().split('\n').map(string => {

return string.trim();

});

main();

});

function readLine() {

return inputString[currentLine++];

}

function regexVar() {

/*

* Declare a RegExp object variable named 're'

* It must match a string that starts with 'Mr.', 'Mrs.', 'Ms.', 'Dr.', or 'Er.',

* followed by one or more letters.

*/

/*

* Do not remove the return statement

*/

let re = new RegExp('^(Mr|Mrs|Ms|Dr|Er)(\\.)([a-zA-Z])*$');

return re;

}

function main() {

const re = regexVar();

const s = readLine();

console.log(!!s.match(re));

}