find (STL Sample)

The sample code below illustrates how to use the find STL function in Visual C++.

Required Header:
<algorithm>

template<class InputIterator, class T> inline
     InputIterator find(InputIterator first, InputIterator last, const T& value)

Note: The class/parameter names in the prototype do not match the version in the header file. Some have been modified to improve readability.

Description:
The find algorithm locates the first element in the range [first, last) that matches value and returns the iterator positioned at the first matching element, or last + 1 if no such element exists.

Sample Code:

//////////////////////////////////////////////////////////////////////
//
// Compile options needed: /GX
//
// find.cpp : Illustrates how to use the find function.
//
// Functions:
//
//   find  - Find the first element in a sequence that matches value.
//////////////////////////////////////////////////////////////////////

// disable warning C4786: symbol greater than 255 character,
// okay to ignore
#pragma warning(disable: 4786)

#include <algorithm>
#include <iostream>

using namespace std;


void main()
{
    const int ARRAY_SIZE = 8 ;
    int IntArray[ARRAY_SIZE] = { 1, 2, 3, 4, 4, 5, 6, 7 } ;

    int *location ;   // stores the position of the first
                      // matching element.

    int i ;

    int value = 4 ;

    // print content of IntArray
    cout << "IntArray { " ;
    for(i = 0; i < ARRAY_SIZE; i++)
        cout << IntArray[i] << ", " ;
    cout << " }" << endl ;

    // Find the first element in the range [first, last + 1)
    // that matches value.
    location = find(IntArray, IntArray + ARRAY_SIZE, value) ;

    //print the matching element if any was found
    if (location != IntArray + ARRAY_SIZE)  // matching element found
        cout << "First element that matches " << value
             << " is at location " << location - IntArray << endl;
    else                                    // no matching element was
                                            // found
        cout << "The sequence does not contain any elements"
             << " with value " << value << endl ;
    }

 

Program Output is:

IntArray { 1, 2, 3, 4, 4, 5, 6, 7,  }

First element that matches 4 is at location 3