2. Double String Characters | JavaScript | Coding Interview | Challenge

You are given a string as an argument. Return a string in which each character is doubled. If any data type other than a string is passed as an argument, return a message that says `not a string!`.

Example:

doubleStrChars('DevLeague') // returns 'DDeevvLLeeaagguuee'

doubleStrChars('Hello!') // returns 'HHeelllloo!!'

doubleStrChars(true) // returns 'not a string!'

doubleStrChars(2468) // returns 'not a string!'

#javascript #interview #codingchallenge #interviewquestions #strings #doblestringcharacters #askfaran