Sort an array of objects by dynamically provided list of object properties in a order by then by style

Question

How to write a generic sorting function in the style orderBy thenBy that sort an array by a list of properties provided as an array.

Answer 1

Do it using Array#sort and Array#reduce methods.

function sortByThenBy(arr, props) {
  // apply custom sort function on array
  return arr.sort(function(a, b) {
    // generate compare function return value by 
    // iterating over the properties array
    return props.reduce(function(bool, k) {
      // if previous compare result is `0` then compare
      // with the next property value and return result
      return bool || (a[k] - b[k]);
      // set initial value as 0
    }, 0);
  })
}

var items = [{
  name: "AA",
  prop1: 12,
  prop2: 13,
  prop3: 5,
  prop4: 22
}, {
  name: "AA",
  prop1: 12,
  prop2: 13,
  prop3: 6,
  prop4: 23
}, {
  name: "AA",
  prop1: 12,
  prop2: 14,
  prop3: 5,
  prop4: 23
}, {
  name: "AA",
  prop1: 11,
  prop2: 13,
  prop3: 5,
  prop4: 22
}, {
  name: "AA",
  prop1: 10,
  prop2: 13,
  prop3: 9,
  prop4: 21
}];

console.log(sortByThenBy(items, ["prop1", "prop3", "prop4"]));

console.log(sortByThenBy(items, ["prop1", "prop3"]));

console.log(sortByThenBy(items, ["prop2", "prop3"]));


function sortByThenBy(arr, props) {
  return arr.sort(function(a, b) {
    return props.reduce(function(bool, k) {
      return bool || (a[k] - b[k]);
    }, 0);
  })
}

.as-console-wrapper {
  max-height: 100% !important;
  top: 0;
}