A promise sample

Promise.js

function find (x) {
  if (x === 10) {
    return Promise.resolve(10);
  } else {
    return new Promise(function (resolve, reject) {
      try {
        if (x === 0) {
          throw ('0 not allowed');
        }
        let t = parseInt(x);
        return resolve(t);
      } catch (e) {
        return reject({error: e});
      }
    });
  }
}

find(5).then(function (data) {
  console.log(data);
});

find(0).then(function (data) {
  console.log(data);
}).catch(function (e) {
  console.log(e);
});

// Promise chaining

function getData5 () {
  return find(5).then(function (data) {
    return data;
  });
}

function getData0 () {
  return find(0).then(function (data) {
    return data;
  }).catch(function (e) {
    return e;
  });
}

function getData10 () {
  return find(10).then(function (data) {
    return data;
  }).catch(function (e) {
    console.log(e);
  });
}

getData5().then(function (response) {
  console.log('Promise chain with Promise object: ', response);
});

getData0().then(function (response) {
  console.log(response);
});

getData10().then(function (response) {
  console.log('Promise chain with Promise.resolve(): ', response);
});