replace


function template
<algorithm>
template < class ForwardIterator, class T >
  void replace ( ForwardIterator first, ForwardIterator last,
                 const T& old_value, const T& new_value );

Replace value in range

Sets all the elements in the range [first,last) whose current value equals old_value to a value of new_value.

The behavior of this function template is equivalent to:
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template < class ForwardIterator, class T >
  void replace ( ForwardIterator first, ForwardIterator last,
                 const T& old_value, const T& new_value )
{
  for (; first != last; ++first)
    if (*first == old_value) *first=new_value;
}


Parameters

first, last
Forward iterators to the initial and final positions in a sequence. The range used is [first,last), which contains all the elements between first and last, including the element pointed by first but not the element pointed by last.
old_value
Value to be replaced.
new_value
Replacement value.


Return value

none

Example

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// replace algorithm example
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

int main () {
  int myints[] = { 10, 20, 30, 30, 20, 10, 10, 20 };
  vector<int> myvector (myints, myints+8);            // 10 20 30 30 20 10 10 20

  replace (myvector.begin(), myvector.end(), 20, 99); // 10 99 30 30 99 10 10 99

  cout << "myvector contains:";
  for (vector<int>::iterator it=myvector.begin(); it!=myvector.end(); ++it)
    cout << " " << *it;

  cout << endl;
 
  return 0;
}


Output:
myvector contains: 10 99 30 30 99 10 10 99


Complexity

Performs as many comparisons as the number of elements in the range [first,last).

See also

replace_if Replace values in range (function template)
replace_copy Copy range replacing value (function template)
remove Remove value from range (function template)
count Count appearances of value in range (function template)
find Find value in range (function template)