const allowed = ["1234", "pass", "apple"]; function passwordChecker(pass) { return allowed.includes(pass); } function login(password) { return new Promise((resolve, reject) => { if (passwordChecker(password)) { resolve({ status: true }); } else { reject({ status: false }); } }); } function checker(pass) { login(pass) .then(token => { console.log("Approve:"); console.log(token); }) .catch(value => { console.log("Reject:"); console.log(value); }) } checker("1234"); checker("wrong");