set find() Function in C++ STL Last Updated : 11 Jul, 2025 Comments Improve Suggest changes Like Article Like Report The std::set::find() is a built-in function in C++ STL that is used to find an element in the set container. It is a member function of std::set container so we can use it directly with any set object.Syntax set_name.find(key) Parameterskey: The element which we have to find.Return ValueIf the element is found, it returns an iterator to its position in the set.If the element is not found, then it returns the iterator to the end.Finding elements in a set is straightforward with the find() function. Example of set::find() C++ // C++ program to demonstrate the use of // set::find() function #include <bits/stdc++.h> using namespace std; int main() { // Create a set set<int> st; st.insert(11); st.insert(14); st.insert(2); st.insert(15); st.insert(3); // key1 find (exist in the set) int key1 = 3; // key2 find (does not exist in the set) int key2 = 1; // Check if key1 is found if (st.find(key1) != st.end()) cout << "Key '" << key1 << "' found" << endl; // Element not present else cout << "Key '" << key1 << "' not found!" << endl; // Check if key2 is found if (st.find(key2) != st.end()) cout << "Key '" << key2 << "' found" << endl; // key2 not found else cout << "Key '" << key2 << "' not found!" << endl; return 0; } OutputKey '3' found Key '1' not found! Complexity Analysis of set::find()Time Complexity: O(log n), where n is the number of elements.Space Complexity: O(1) Comment More infoAdvertise with us G gopaldave Follow Improve Article Tags : Misc C++ STL CPP-Functions cpp-set +1 More Practice Tags : CPPMiscSTL Explore C++ Programming Language 5 min read C++ OverviewIntroduction to C++ Programming Language 3 min read Features of C++ 5 min read History of C++ 7 min read Interesting Facts about C++ 2 min read Setting up C++ Development Environment 8 min read Difference between C and C++ 3 min read C++ BasicsUnderstanding First C++ Program 4 min read C++ Basic Syntax 4 min read C++ Comments 3 min read Tokens in C 4 min read C++ Keywords 2 min read Difference between Keyword and Identifier in C 3 min read C++ Variables and ConstantsC++ Variables 4 min read Constants in C 4 min read Scope of Variables in C++ 7 min read Storage Classes in C++ with Examples 6 min read Static Keyword in C++ 5 min read C++ Data Types and LiteralsC++ Data Types 7 min read Literals in C 4 min read Derived Data Types in C++ 4 min read User Defined Data Types in C++ 4 min read Data Type Ranges and Their Macros in C++ 3 min read C++ Type Modifiers 4 min read Type Conversion in C++ 4 min read Casting Operators in C++ 5 min read C++ OperatorsOperators in C++ 9 min read C++ Arithmetic Operators 4 min read Unary Operators in C 5 min read Bitwise Operators in C 6 min read Assignment Operators in C 4 min read C++ sizeof Operator 3 min read Scope Resolution Operator in C++ 4 min read C++ Input/OutputBasic Input / Output in C++ 5 min read cin in C++ 4 min read cout in C++ 2 min read Standard Error Stream Object - cerr in C++ 2 min read Manipulators in C++ 4 min read C++ Control StatementsDecision Making in C (if , if..else, Nested if, if-else-if ) 7 min read C++ if Statement 3 min read C++ if else Statement 3 min read C++ if else if Ladder 3 min read Switch Statement in C++ 5 min read Jump statements in C++ 4 min read C++ Loops 7 min read for Loop in C++ 6 min read Range-Based for Loop in C++ 3 min read C++ While Loop 3 min read C++ do while Loop 4 min read C++ FunctionsFunctions in C++ 8 min read return Statement in C++ 4 min read Parameter Passing Techniques in C 3 min read Difference Between Call by Value and Call by Reference in C 4 min read Default Arguments in C++ 5 min read Inline Functions in C++ 6 min read Lambda Expression in C++ 4 min read C++ Pointers and ReferencesPointers and References in C++ 5 min read C++ Pointers 8 min read Dangling, Void , Null and Wild Pointers in C 6 min read Applications of Pointers in C 4 min read Understanding nullptr in C++ 3 min read References in C++ 5 min read Can References Refer to Invalid Location in C++? 2 min read Pointers vs References in C++ 5 min read Passing By Pointer vs Passing By Reference in C++ 5 min read When do we pass arguments by pointer? 5 min read Like