This code isn't working probably, because the connection to mongo isn't established fast enough. So I thought that I have to change it to a asnyc function. But definetly doesn't know where to start. I'm new to Node and Mongo

It should looks like that, but mongo updates it that every rank is the same digit.

// function for giving rank
function giveRank(arrayArg,resultArg){
  // declaring and initilising variables
    let rank = 1;
    prev_rank = rank;
    position = 0;
    // displaying the headers in the console
    console.log('\n-------OUR RESULTS------\n');
    console.log('Name | Mark | Position\n');
    // looping through the rank array
    for (i = 0; i < arrayArg.length ; i   ) {
            /*
            If it is the first index, then automatically the position becomes 1.
            */
            if(i == 0) {
                position = rank;
            Ranking.find({name: arrayArg[i]}).then((data) => {
                if(data){
                updateRank(bla, bla, bla)
                }else{
                newRank(bla,bla,bla);
                }
            });
            
            /*
            if the value contained in `[i]` is not equal to `[i-1]`, increment the `rank` value and assign it to `position`.
            The `prev_rank` is assigned the `rank` value.
            */
            } else if(arrayArg[i] != arrayArg[i-1]) {
            rank   ;
            position = rank;
            prev_rank = rank;
            Ranking.find({name: arrayArg[i]}).then((data) => {
                if(data){
                updateRank(bla, bla, bla)
                }else{
                newRank(bla,bla,bla);
                }
            });
            
            /*
            Otherwise, if the value contained in `[i]` is equal to `[i-1]`,
            assign the position the value stored in the `prev_rank` variable then increment the value stored in the `rank` variable.*/
            } else {
                position = prev_rank;
                rank   ;
                Ranking.find({name: arrayArg[i]}).then((data) => {
                if(data){
                updateRank(bla, bla, bla)
                }else{
                newRank(bla,bla,bla);
                }
            });
            }
    }
}

CodePudding user response：

To convert a promise-chain-based asynchronous call into an async/await call, you only need to do a couple things:

1. Convert the parent function into an async function by using the async keyword, like so: function myFunction (...) {} turns into async function myFunction (...) {}

2. Use the await keyword in front of your function call, like so: doStuff(...) turns into await doStuff(...)

3. Convert the parameter to your first .then() callback to the return value of the async call, like so: doStuff().then((data) => {}) turns into let data = await doStuff()

4. Move the body of the .then() callback below the assignment of the response, like so: doStuff().then((data) => { console.log(data) }) turns into let data = await doStuff(); console.log(data);

So in your example, converting one of the functions would look like so:

async function giveRank(arrayArg,resultArg){
...
...
  if(i == 0) {
    position = rank;
    let data = await Ranking.find({name: arrayArg[i]})
    if(data){
      updateRank(bla, bla, bla)
    }else{
      newRank(bla,bla,bla);
    }
  }
...
...
}