sortBy function

List<Map<String, dynamic>> sortBy(List<Map<String, dynamic>> collection, List iteratees)

Sorts a list of maps collection based on the provided list of iteratees.

Sorts the list of maps collection based on the values of keys specified in the list iteratees.

The collection parameter is a list of maps (List<Map<String, dynamic>>) to be sorted. The iteratees parameter is a list of dynamic values or functions that specify the keys or custom comparison functions for sorting.

If an element in iteratees is a function, it is applied to each map in collection, and the return values are used for comparison. If an element in iteratees is a string, it represents the key in each map to be used for comparison.

Returns the sorted list of maps collection.

Example:

var data = [
  {'name': 'John', 'age': 30},
  {'name': 'Jane', 'age': 25},
  {'name': 'Bob', 'age': 35}
];

var sortedByName = sortBy(data, ['name']);
print(sortedByName); // Output: [{'name': 'Bob', 'age': 35}, {'name': 'Jane', 'age': 25}, {'name': 'John', 'age': 30}]

var sortedByAge = sortBy(data, [(person) => person['age']]);
print(sortedByAge); // Output: [{'name': 'Jane', 'age': 25}, {'name': 'John', 'age': 30}, {'name': 'Bob', 'age': 35}]

Implementation

List<Map<String, dynamic>> sortBy(
    List<Map<String, dynamic>> collection, List<dynamic> iteratees) {
  collection.sort((a, b) {
    for (var iteratee in iteratees) {
      if (iteratee is Function) {
        var aValue = iteratee(a);
        var bValue = iteratee(b);
        if (aValue != bValue) {
          return aValue.compareTo(bValue);
        }
      } else if (a[iteratee] != b[iteratee]) {
        return a[iteratee].compareTo(b[iteratee]);
      }
    }
    return 0;
  });
  return collection;
}