Day 7: Regular Expressions II

Task

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

• String s starts with the prefix Mr., Mrs., Ms., Dr., or Er.
• The remainder of string s (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 s is >= 3.

Output Format

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

Sample Input 0

1

Mr.X

Sample Output 0

1

true

Explanation 0

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

Sample Input 1

1

Mrs.Y

Sample Output 1

1

true

Explanation 1

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

Sample Input 2

1

Dr#Joseph

Sample Output 2

1

false

Explanation 2

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

Sample Input 3

1

Er .Abc

Sample Output 3

1

false

Explanation 3

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

Solution

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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.
     */
    const re = new RegExp(/^(Mr\.|Dr\.|Er\.|Ms\.|Mrs\.)\s?[a-z|A-Z]+$/);
    /*
     * Do not remove the return statement
     */
    return re;
}