ary = ['Spring','Summer','Fall','Winter']; str = ary.join(','); console.log(str); //=>Spring,Summer,Fall,Winter str = 'Spring,Summer,Fall,Winter'; ary = str.split(','); console.log(ary); //=>["Spring", "Summer", "Fall", "Winter"] Register as a new user and use Qiita more conveniently You get articles that match your needsYou can efficiently read back useful informationYou can use dark themeWhat yo