How to sort an array of names, relevant to the value of an integer in the same object as the name?

Question

This is the object for the array below.

function Employee (name,preference,man,max){
  // Defines the object employee with the relevant fields
  this.name = name;
  // slot preference in order
  this.preference = preference;
  // Number of mandatory slots required
  this.man = man;
  // Maximum number of slots that can be allocated
  this.max = max;
}

This is the array below. The second fields values (which represent slots in a timetable) are ordered by preference already. I want to be able to choose a particular slot and alert a list which contains all those who have it in their preference field and in order of who placed it of the highest preference.

var staff = new Array();
staff.push(new Employee("john",[1,2,3],1,3));
staff.push(new Employee("Conrad",[2,1,4],1,3));
staff.push(new Employee("Elliot",[8,2,6,7,1],3,5));
staff.push(new Employee("Sarah",[3,1,4,2,6],3,5));
staff.push(new Employee("Emily",[7,2,8,1,4],3,5));
staff.push(new Employee("Mark",[3,4,1,2],1,3));
staff.push(new Employee("Lucy",[5,1,4],1,3));
staff.push(new Employee("Sam",[6,2,7],1,3));
showEmployees(staff);

score 1 · Accepted Answer · answered Nov 25 '14 at 12:23

There are 3 steps to this:

Filter the list to only get people with that preference - use filter().
Sort the result to order by preference position - use sort().
Convert the results to a comma-separated string of names to show in the alert - use map().

function Employee(name, preference, man, max) {
    // Defines the object employee with the relevant fields
    this.name = name;
    // slot preference in order
    this.preference = preference;
    // Number of mandatory slots required
    this.man = man;
    // Maximum number of slots that can be allocated
    this.max = max;

}

var staff = new Array();
staff.push(new Employee("john", [1, 2, 3], 1, 3));
staff.push(new Employee("Conrad", [2, 1, 4], 1, 3));
staff.push(new Employee("Elliot", [8, 2, 6, 7, 1], 3, 5));
staff.push(new Employee("Sarah", [3, 1, 4, 2, 6], 3, 5));
staff.push(new Employee("Emily", [7, 2, 8, 1, 4], 3, 5));
staff.push(new Employee("Mark", [3, 4, 1, 2], 1, 3));
staff.push(new Employee("Lucy", [5, 1, 4], 1, 3));
staff.push(new Employee("Sam", [6, 2, 7], 1, 3));

// the preference to search on
var pref = 2;

var results = staff.filter(function (v) {
    // return true if pref is in the list
    return v.preference.indexOf(pref) > -1;
}).sort(function (a, b) {
    // compare position of pre in each preference list
    return a.preference.indexOf(pref) < b.preference.indexOf(pref) ? -1
        : a.preference.indexOf(pref) > b.preference.indexOf(pref) ? 1 : 0;
}).map(function (e) {
    // just return the name of the person
    return e.name;
}).join(', '); // join names into comma-separated list

alert(results);

Thank you this has helped a lot : – Big Dirty Nov 26 '14 at 09:41 — Big Dirty, Nov 26 '14 at 09:41

score 0 · Answer 2 · edited May 23 '17 at 11:57

Their preference ordering can be determined by the index at which that slot is listed in the array - so you'd used indexOf to find that, and then you can compare those indices just as you would compare any other properties.

indexOf would return -1 if the item does not occur in the array, which would make the highest preference actually. However, as we filter those out that don't have them in their preference field we don't need to care about that.

var slot = …;
staff.filter(function(employee) {
    return employee.preference.indexOf(slot) > -1;
}).sort(function(a, b) {
    return a.preference.indexOf(slot) - b.preference.indexOf(slot);
});

How to sort an array of names, relevant to the value of an integer in the same object as the name?

2 Answers2

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