STL Sample for the find Function

ID: Q156302

The information in this article applies to:

The Standard C++ Library included with: - Microsoft Visual C++, 32-bit Edition, version 4.2

SUMMARY

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

MORE INFORMATION

Required Header

   <algorithm>

Prototype

   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.
// 
// Written by Kalindi Sanghrajka
// of Microsoft Product Support Services,
// Software Core Developer Support.
// Copyright (c) 1996 Microsoft Corporation. All rights reserved.
////////////////////////////////////////////////////////////////////// 

// disable warning C4786: symbol greater than 255 character,
// okay to ignore

#pragma warning(disable: 4786)

#include <algorithm>
#include <iostream>

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 ;
    }

Output:

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

First element that matches 4 is at location 3

REFERENCES

Visual C++ Books On Line: Visual C++ Books:C/C++:Standard C++ Library Reference.

Additional query words: STL find

Keywords          : kbcode STLIss 
Version           : WINNT:4.2;
Platform          : NT WINDOWS
Issue type        : kbhowto

Last Reviewed: October 10, 1997