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Overview

This code snippet shows how to use the C++ Standard Template Library (STL) sort function with predefined data types. The sort function needs at least two parameters: start and end. These iterator parameters are used to sort the range of elements between them. An optional third parameter has the default less-than operator as a value to compare elements.

Some STL containers cannot use regular the sort function and they provide specialized versions of sort as a member function. The list container is one of them and it also has an optional default value to compare elements.

Note: In order to use this code, you need to install the Open C/C++ plug-in.

This snippet can be self-signed.

MMP file

The following libraries are required:

LIBRARY  libstdcpp.lib
LIBRARY  libc.lib
LIBRARY  euser.lib

Source file

#include <iostream>
#include <algorithm>
#include <list>
#include <vector>
#include <string>
 
using namespace std;
 
 
bool exampleCompare(string& s1, string& s2)
{
  // compare string lengths
  int len1 = s1.length();
  int len2 = s2.length();
 
  return len1 < len2;
 
}
 
int main()
{
  //-- Sorting predefined data types --
 
  // 1) int array
  int intArray[] = { 3, 1, 2 };
  int arrayElements = sizeof(intArray) / sizeof(intArray[0]); 
  
  sort(intArray, intArray + arrayElements);
  for (int i=0; i<arrayElements; ++i) 
     cout << intArray[i] << ' '; //1 2 3
 
  // 2) int vector
  vector<int> intVector;
  intVector.push_back(3);
  intVector.push_back(1);
  intVector.push_back(2);
  int vectorElements = intVector.size();
  
  sort(intVector.begin(), intVector.end());
  for (int i=0; i<vectorElements; ++i) 
  cout << intVector[i] << ' '; //1 2 3
 
 
  // 3) string list
  list<string> stringList;
  list<string>::iterator stringIterator;
 
  stringList.push_back ("second");
  stringList.push_back ("first");  
  stringList.push_back ("third");
  
  stringList.sort();
  for (stringIterator = stringList.begin(); 
  stringIterator != stringList.end(); 
  ++stringIterator)
  cout << *stringIterator << ' '; //first second third
 
  //use function exampleCompare to sort list again
  stringList.sort(exampleCompare);
  
  for (stringIterator = stringList.begin();                                        
   stringIterator != stringList.end(); 
   ++stringIterator)
   cout << *stringIterator << ' '; //first third second
 
  return 0;
}

Postconditions

The STL sort function is used to sort arrays, vectors, and lists and the sorted values are displayed on the screen.

See also

CS001099 - Sorting class and struct types using STL sort