Sorting in Javascript based on 2 parameters-CodePudding

I have a use case wherein I want to sort the below given array

const account = [
{
    currency: "CNY",
    available_balance: 1000
}, 
{
    currency: "HKD",
    available_balance: 100
}, 
{
    currency: "CNY",
    available_balance: 200
}, 
{
    currency: "HKD",
    available_balance: 1500
}];

Now I have to sort it as follows,

const output = [
{
    currency: "CNY",
    available_balance: 1000
},
{
    currency: "CNY",
    available_balance: 200
},
{
    currency: "HKD",
    available_balance: 1500
},
{
    currency: "HKD",
    available_balance: 100
}];

The one with higher balance in CNY is first followed by the lower balances of CNY. After that I want to display HKD with higher balance first.

I was able to sort according to the available_balance but with not currency.

sortedAccount = account.sort((a, b) => {
return b.available_balance - a.available_balance;
});
console.log(sortedAccount);

Please help :) Thank you.

CodePudding user response：

The general pattern for multi-field sorts is:

sortedAccount = account.sort((a, b) => {
  let res = a.currency.localeCompare(b.currency)
  if (res) return res
  res = b.available_balance - a.available_balance
  return res
});

You keep letting the result fall through to the next condition if '0'.

This solution will sort on language ascending and then balance descending.

CodePudding user response：

You can combine this with an || expression:

sortedAccount = account.sort((a, b) => {
  return a.currency.localeCompare(b.currency) ||    // Ascending currency
         b.available_balance - a.available_balance; // Descending balance
});