Asynchronously solution to check data from database kinds of loop clause

Question

What I want to do is asynchronously check from database and get a result from it? In my application I am trying to implement Asynchronously to resolve this steps as

Answer 1

You can substitute Promise.all(), Array.prototype.map() for for loop

function registeredUsers(data) {
    return Promise.all(data.map(function(curr, i) {
        var mobileNumber = curr.mobileNumber.substr(1, curr.mobileNumber.length);
        return checkUserMobileNumberAsEwallet(mobileNumber)
        .then(function (_mobileNumber) {
            return {ewalletNumber: _mobileNumber};
        });
    }))
    .then(function(accountNumbers) {
        console.log(accountNumbers);
        return accountNumbers
    })
    .catch(function(err) {
        console.log(err);
    })
}

see also How do I return the response from an asynchronous call?