var database = [ { username: "Rafnexx", password: "passw0rd" }, { username: "admin", password: "haslo" }, { username: "johny", password: "haslo" }, { username: "mnemonic", password: "haslo" }, { username: "tibia", password: "haslo" }, ]; var newsfeed = [ { username: "John", timeline: "I'm tired!" }, { username: "Szymon", timeline: "That's so exciting!" }, { username: "Patryk", timeline: "Tomorrow, I'll destroy you guys!" } ]; var userNamePrompt = prompt("What's your username?"); var passwordPrompt = prompt("What's your password?"); function checkingUserNameAndPassword(user, pass) { return database.some( name => name.username == user) && database.some( name => name.password == pass); } function signingIn() { checkingUserNameAndPassword(userNamePrompt, passwordPrompt) ? console.log(newsfeed) : console.log("Błędna nazwa użytkownika lub hasło!"); } } signingIn();