Find max number based on two fields in an array

August 18, 2022

Suppose we have an array

[{no:1,count:1},{no:2,count:1},{no:2,count:2},{no:3,count:1},{no:4,count:1},{no:5,count:1}]

So I would like to find the top 5 no in this array but if two numbers are equal then the one with the higher count should be selected for example in the above case the top 5 should be

[{no:5,count:1},{no:4,count:1},{no:3,count:1},{no:2,count:2},{no:1,count:1}]

>Solution :

It’s easy enough to write your own comparison function:

function compare( a, b ) {
  if ( a.no < b.no ){
    return 1;
  }
  if ( a.no > b.no ){
    return -1;
  }

  if( a.no === b.no) {
    if ( a.count < b.count ){
      return 1;
    }
    if ( a.count > b.count ){
      return -1;
    }
  }
  return 0;
}

const data = [
  {no:1,count:1},
  {no:2,count:1},
  {no:2,count:2},
  {no:3,count:1 },
  {no:4,count:1},
  {no:5,count:1}
];
data.sort( compare );