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unordered_map find() Function in C++ with Examples

C++ unordered_map find() Function: Here, we will learn about the find() function, its usages, syntax and examples.
Submitted by Shivang Yadav, on July 20, 2022

An unordered_map is a special type of container that stores data in the form of key-value pairs in an unordered manner. The key stored is used to identify the data value mapped to it uniquely.

C++ STL std::unordered_map::find() Function

The find() function is used to check for the presence of the pair with the given key value in the unordered_map.

Syntax

unordered_mapName.find(k);
// k is the key value to be found

Parameter(s)

It accepts a single parameter which is the key to be searched for.

Return value

It returns an iterator that points to the element's key value if it is found otherwise it returns the end of the map iterator.

Sample Input and Output

CASE 1:
Input: unordered_map = {{1, a}, {2, e}, {10, a}}
key = 2
Output: key-value present.

CASE 2:
Input: unordered_map ={{1, a}, {2, e}, {10, a}}
key = 5
Output: key-value not present.

Example

#include <iostream>
#include <unordered_map>
using namespace std;

int main()
{
    unordered_map<int, char> myUnorderedMap = { { 1, 'a' }, { 5, 'x' }, { 9, 's' } };

    cout << "The elements of unordered_map are ";
    for (auto x : myUnorderedMap)
        cout << x.first << " : " << x.second << "\t";
    cout << endl;

    int k = 9;
    cout << "The element " << k << " is ";
    (myUnorderedMap.find(k) == myUnorderedMap.end()) ? cout << "Not Present\n" : cout << "Present\n";

    k = 67;
    cout << "The element " << k << " is ";
    (myUnorderedMap.find(k) == myUnorderedMap.end()) ? cout << "Not Present\n" : cout << "Present\n";

    return 0;
}

Output

The elements of unordered_map are 9 : s 5 : x   1 : a
The element 9 is Present
The element 67 is Not Present