How to sort an array by item type where strings should appear 1st then floats and integers while keeping same type precedence and no extra arrays used

Question

Input:

[7,"a","b",5, 0.1, "c", 0.5, 9, 1, "e", "m", 0.3, 8.5, 74, 89,"f","r",0.5 ,"x", "y", 4, 7]

Output:

["a", "b", "c", "e", "m", "f", "r", "x", "y", 0.1, 0.5, 0.3, 8.5, 0.5, 7, 5, 9, 1, 74, 89, 4, 7]

function sorter(arr) {
    var arr1, arr2, arr3;
    arr1 = [];
    arr2 = [];
    arr3 = [];
    for (var i = 0; i < arr.length; i++) {
        if (typeof arr[i] === "string") {
            arr1.push(arr[i]);
        } else if (typeof arr[i] === 'number' && !isNaN(arr[i])) {
            if (Number.isInteger(arr[i])) {
                arr3.push(arr[i]);
            } else {
                arr2.push(arr[i]);
            }
        }
    }
    return [...arr1, ...arr2, ...arr3];
}

Answer 1

An approach based on a single sort comparator callback ...

function orderByItemTypeOnly(a, b) {
  const precedences = {
    'string': 1,
    'float': 2,
    'int': 3,
  };
  const getType = val =>
    ((typeof val === 'number') && Number.isFinite(val))
      ? Number.isInteger(val) && 'int' || 'float'
      : (typeof val);

  const aType = getType(a);
  const bType = getType(b);

  return (
    (precedences[aType] || 4) - (precedences[bType] || 4)
  );
}

console.log([

  7, "a", "b", 5, 0.1, "c", 0.5, 9, 1, "e", "m",
  0.3, 8.5, 74, 89, "f", "r", 0.5, "x", "y", 4, 7

].sort(orderByItemTypeOnly));

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

There is also the possibility of solving this task not by sort but based on a reduce approach ...

function collectAndShiftItemByType(list, item, idx, arr) {
  if (list.length === 0) {
    list.push([], [], [], []);
  }
  const typeListIndex = ((typeof item === 'number') && Number.isFinite(item))
    ? (Number.isInteger(item) && 2 || 1)
    : (typeof item === 'string') ? 0 : 3;

  // push into sub lists ... [0]string, [1]float, [2]integer, [3]unknown.
  list[typeListIndex].push(item);

  if (idx >= arr.length - 1) {
    list = list[0]
      .concat(list[1])
      .concat(list[2])
      .concat(list[3]);
  }
  return list;
}

console.log([

  7, "a", "b", 5, 0.1, "c", 0.5, 9, 1, "e", "m",
  0.3, 8.5, 74, 89, "f", "r", 0.5, "x", "y", 4, 7

].reduce(collectAndShiftItemByType, []));

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