Logo

Programming-Idioms

Sort the elements of the list (or array-like collection) items in ascending order of x.p, where p is a field of the type Item of the objects in items.
New implementation

Be concise.

Be useful.

All contributions dictatorially edited by webmasters to match personal tastes.

Please do not paste any copyright violating material.

Please try to avoid dependencies to third-party libraries and frameworks.

Other implementations
with Ada.Containers.Vectors;
use Ada.Containers;
declare
   function Compare_Function (Left, Right : Item) return Boolean is (Left.P < Right.P);
   
   package Item_Vector_Sorting is new Item_Vectors.Generic_Sorting (Compare_Function);

   use Item_Vector_Sorting;
begin
   Sort (Items);
end;
#include <stdlib.h>
int compareProp (const void *a, const void *b)
{
    return (*(const Item**)a)->p - (*(const Item**)b)->p;
}

qsort(items, N, sizeof(Item*), compareProp);
(sort-by :p items)
#include <algorithm>
struct {
    bool operator()(const Item &lhs, const Item &rhs) const { return lhs.p < rhs.p; }
} custom_sort;

std::sort(begin(items), end(items), custom_sort);
#include <algorithm>
std::sort(begin(items), end(items), [](const auto& a, const auto& b) { return a.p < b.p; });
using System.Collections.Generic;
System.Array.Sort(items, Comparer<Item>.Create((a, b) => a.p - b.p));
using System.Linq;
items.OrderBy(x => x.p)
import std.algorithm.sorting;
sort!("a.p < b.p")(items);
items.sort((a, b) => Comparable.compare(a.p, b.p));
items.sort((a, b) => (a.p).compareTo(b.p));
Enum.sort_by(items, &(&1.p))
	
sort_by_birth(ListOfMaps) ->
  lists:sort(
    fun(A, B) ->
      maps:get(birth, A, undefined) =< maps:get(birth, B, undefined)
    end, ListOfMaps).

sort_by_birth(ListOfRecords) -> lists:keysort(#item.birth, ListOfRecords).
import "slices"
import "cmp"
compare := func(a, b Item) int {
	return cmp.Compare(a.p, b.p)
}
slices.SortFunc(items, compare)
import "sort"
type ItemPSorter []Item
func (s ItemPSorter) Len() int{ return len(s) }
func (s ItemPSorter) Less(i,j int) bool{ return s[i].p<s[j].p }
func (s ItemPSorter) Swap(i,j int) { s[i],s[j] = s[j],s[i] }

func sortItems(items []Item){
	sorter := ItemPSorter(items)
	sort.Sort(sorter)
}
import "sort"
less := func(i, j int) bool {
	return items[i].p < items[j].p
}
sort.Slice(items, less)
items.sort { x -> x.p }
items.sort { x, y -> x.p <=> y.p }
sortBy (comparing p) items
import qualified Data.List as List
List.sortOn p items
items.sort(function(a,b) {
  return compareFieldP(a.p, b.p);
});
import java.util.Arrays;
import java.util.Comparator;
Arrays.sort(items, new Comparator<Item>(){
	public int compare(Item a, Item b){
		return a.p - b.p;
	}
});
import java.util.Comparator;
items.stream().sorted(Comparator.comparing(x -> x.p))
import java.util.Collections;
import java.util.Comparator;
Collections.sort(items, new Comparator<Item>(){
	@Override
	public int compare(Item a, Item b){
		return a.p - b.p;
	}
});
items.sortedBy { it.p }
(sort #'< items :key #'p)
table.sort(items, function(a,b)
	if a.p < b.p then return true end
end)
@import Foundation;
[items sortedArrayUsingDescriptors:@[[NSSortDescriptor sortDescriptorWithKey:@"p" ascending:YES]]]
function cmp($a, $b)
{
    if ($a->p == $b->p) {
        return 0;
    }

    return ($a->p < $b->p) ? -1 : 1;
}

usort($items, 'cmp');
uses fgl;
type

  TItem = class p: Integer; end;
  TItems = specialize TFPGObjectList<TItem>;

var items: TItems;

  function compare(const a, b: TItem): Integer;
  begin
    Result := a.p - b.p;
  end;

begin
  items := TItems.Create;
  // Add items here.
  items.Sort(@compare);
end.  
@items = sort { $a->{p} cmp $b->{p} } @items;
items = sorted(items, key=lambda x: x.p)
from operator import attrgetter
items = sorted(items, key=attrgetter('p'))
items.sort_by(&:p)
items.sort_by(|a,b| a.p.cmp(&b.p));
items.sort_by_key(|x| x.p);
items.sortBy(_.x)
case class S(x: Int)
val items = List(S(3), S(4), S(2))
items.sortBy( item: S => item.x )
(define-struct item (p x y) #:transparent)
(define items (list (item 1 2 3) (item 0 0 0) (item 5 2 1)))
(sort items < #:key item-p)
items sorted: [:x :y | x p <= y p].
Imports System.Linq
items.OrderBy(Function(x) x.p)
Imports System.Collections.Generic
System.Array.Sort(items, Comparer(Of Item).Create(Function(a, b) a.p - b.p))