Sorting

Sort an Array of Strings, from large to small and lexicographic for Strings of equal length

Perl

Interpeter: Perl

Numeric sort

my @sorted = sort {$a<=>$b} (3, 6, 4, 5, 2, 7, 1);

Alpha-Numeric sort

my @sorted = sort ('this', 'that', 'and', 'the', 'other');

Numeric sort or Alpha-Numeric sort if a numeric sort cannot be done

# note, this can be a oneliner
my @sorted = sort {
   ($a =~ /^\-?\d+\.?\d*$/ and $b =~ /^\-?\d+\.?\d*$/) ? $a <=> $b : $a cmp $b
} ('this', 'that', 'and', 'the', 'other', 3, 6, 4, 5, 2, 7, 1);

Python

Interpreter: Python 2.5

Python's lists have a method for in-place sorting; there's also a built-in sorted() method that can sort any iterable.

# create a sample list
words = ['Long', 'words', 'are', 'more', 'interesting', 'than', 'short', 'ones']

# order it and keep the result on another variable
sorted_words = sorted(words, key = lambda word: (-len(word), word))

# sorted_words: ['interesting', 'short', 'words', 'Long', 'more', 'ones', 'than', 'are']

Ruby

#create a test array
ary=['Long','words','are','more','interesting','than','short','ones']
ary.sort_by {|a| [-a.size,a]}
# => ["interesting", "short", "words", "Long", "more", "ones", "than", "are"]

UNIX Shell

words='Long words are more interesting than short ones'
sorted_words="$(
  for word in $words # doesn't work with ZSH since it won't do field splitting here
  do echo "$word"
  done | sort | \
    while read word
    do echo -n "$word "
    done
  echo
 )"
echo "$sorted_words"

C++

 #include <algorithm>

 // sort an array
 int arr[] = { 3, 8, 5, 2, 9 };
 int arr_length = sizeof(arr)/sizeof(arr[0]);
 std::sort(arr, arr+arr_length);

 // sort a std-vector
 std::vector<int> vec;
 vec.push_back(5);
 vec.push_back(4);
 vec.push_back(7);
 vec.push_back(1);
 std::sort(vec.begin(), vec.end());

 // Sort an array in a custom way with a function.
 // This also works on std-vectors.
 // Note: of course the function is_bigger should be outside our function.
 bool is_bigger(int a, int b)
 {
   // note: for equal elements it should return false
   return a>b;
 }
 std::sort(arr, arr+arr_length, is_bigger);

 // Sort an array in a custom way with a function object.
 // This has the advantage that you can give a state to the sorting object.
 // This also works on std-vectors.
 // Note: the struct compare_modulo should be outside our function.
 struct compare_modulo
 {
   int mod;
   compare_modulo(int m): mod(m) {}
   bool operator()(int a, int b) const
   {
     // note: for equal elements it should return false
     return (a%mod)<(b%mod);
   }
 }
 std::sort(arr, arr+arr_length, compare_modulo(3));