smiley.md

Given an array (arr) as an argument complete the function countSmileys that should return the total number of smiling faces. Rules for a smiling face:

• Each smiley face must contain a valid pair of eyes. Eyes can be marked as : or ;
• A smiley face can have a nose but it does not have to. Valid characters for a nose are - or ~
• Every smiling face must have a smiling mouth that should be marked with either ) or D
• No additional characters are allowed except for those mentioned.
• Valid smiley face examples: :) :D ;-D :~)
• Invalid smiley faces: ;( :> :} :]

Regex solution

function countSmileys(arr) {
  const SMILEYS = /^[:;][-~]?[\)D]$/
  return arr.filter(smiley => SMILEYS.test(smiley)).length
}