Suppose I have this data

and for the grade

suppose i declare the script as

 let data = [
  [John, 76],
  [Jack, 55],
  [Dani, 90]
];

The program should assign the grade with the corresponding mark, how do I sort the grade since we know we cant change the index for mark as usual because each mark assign to different student? The output should display all data in descending order as

CodePudding user response：

I would break it up into different functions so that you can handle each task separately. Then you can combine them to produce your desired result, like this:

const grades = [
  ['A', 80],
  ['B', 60],
  ['C', 40],
];

function getGrade (mark) {
  for (const [grade, minMark] of grades) {
    if (mark < minMark) continue;
    return grade;
  }
  return 'F'; // use minimum grade as default if mark is too low
}

function sortByHighestMark (a, b) {
  return b.mark - a.mark;
}

const data = [
  ['John', 76],
  ['Jack', 55],
  ['Dani', 90]
];

const result = data
  .map(([name, mark]) => ({grade: getGrade(mark), name, mark}))
  .sort(sortByHighestMark);

console.log(result);

// and data is unmodified:
console.log(data);

CodePudding user response：

If you mean that you expect output like:

Dani - A
John - B
Jack - C

Then I would do something like:

A method:

getGrade(points => {
  if(points >= 80 && points <= 100) return 'A'
  if(points >= 60 && points < 80) return 'B'
  return 'C'
})

Then have data as:

    const data = [
                 {name: 'John', value: 76},
                 {name: 'Jack', value: 55},
                 {name: 'Dani', value: 90},
                 ]

Then just do:

data.sort((student1, student2) => {
 if(getGrade(student1.value) === student2.value) return 0
 return (getGrade(student1.value) > getGrade(student2.value))? 1 : -1
})

I hope I understood you correct?