Best Way to Get Objects with Highest Property Value

Question

I have the following multidimensional array of student objects:

var students = [
{name: \"Jack\", age: \"NYN\", attempts: 3, wrong: 2},
{name: \"Phil\", age: \"N         


        

Answer 1

The most straight-forward algorithm to achieve your goal would be:

1. Find the maximum value for wrong within students array.
2. Use filter to leave only the relevant students (with the property wrong equals the maximum).

var students = [{name: "Jack", age: "NYN", attempts: 3, wrong: 2},{name: "Phil", age: "NNNY", attempts: 4, wrong: 3},{name: "Tom", age: "", attempts: 0, wrong: 0},{name: "Lucy", age: "YYNY", attempts: 4, wrong: 1},{name: "Ben", age: "NYNN", attempts: 4, wrong: 3},{name: "Hardest", age: "NNN", attempts: 3, wrong: 3}];

// Find the maximum 'wrong' value
let maxValue = 0;
for(let student of students) {
  if(student.wrong > maxValue) {
    maxValue = student.wrong;
  }
}

// filter out the students with 'wrong' value different than the maximum
let onlyMax = students.filter(item => item.wrong == maxValue);
console.log(onlyMax);

Note all the algorithm does is iterating the array twice, resulting in run-time of O(2n) = O(n).

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The more general solution allows one to find the items with maximum value of property in an objects array:

var students = [{name: "Jack", age: "NYN", attempts: 3, wrong: 2},{name: "Phil", age: "NNNY", attempts: 4, wrong: 3},{name: "Tom", age: "", attempts: 0, wrong: 0},{name: "Lucy", age: "YYNY", attempts: 4, wrong: 1},{name: "Ben", age: "NYNN", attempts: 4, wrong: 3},{name: "Hardest", age: "NNN", attempts: 3, wrong: 3}];

function filterByMax(arr, property) {
  // Find the maximum 'wrong' value
  let maxValue = 0;
  for(let item of arr) {
    if(item[property] > maxValue) {
      maxValue = item[property];
    }
  }
  
  // filter out the students with 'wrong' value different than the maximum
  return arr.filter(item => item[property] == maxValue);
}

console.log(filterByMax(students, 'wrong'));