for_each

Apply a function to every item in a range.

Apply f to every element in the range [ first , last) and return the input parameter f .

Library

Standards<ToolKit>

Declaration


#include <algorithm>

template< class InputIterator, class Function >
Function for_each
  (
  InputIterator first,
  InputIterator last,
  Function f
  );

Complexity

Time complexity is linear, as function is called ( last - first ) times. Space complexity is constant.

Example <ospace/osstd/examples/foreach0.cpp>
#include <iostream>
#include <algorithm>

void
print( int a_ )
  {
  cout << a_ << ` `;
  }

int numbers[ 10 ] = { 1, 1, 2, 3, 5, 8, 13, 21, 34, 55 };

void
main()
  {
  for_each( numbers, numbers + 10, print );

  cout << "\n";
  }

1 1 2 3 5 8 13 21 34 55
Example <ospace/osstd/examples/foreach1.cpp>
#include <iostream>
#include <algorithm>
#include <vector>

void
print_sqr( int a_ )
  {
  cout << a_ * a_ << " ";
  }

void
main()
  {
  vector< int > v( 10 );
  for ( size_t i = 0; i < v.size(); ++i )
    v[ i ] = i;

  for_each( v.begin(), v.end(), print_sqr );

  cout << "\n";
  }

0 1 4 9 16 25 36 49 64 81

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