# multiset upper_bound() in C++ STL with Examples

• Difficulty Level : Basic
• Last Updated : 01 Apr, 2021

The multiset::upper_bound() is a built-in function in C++ STL that returns an iterator pointing to the immediate next element which is just greater than k. If the key passed in the parameter exceeds the maximum key in the container, then the iterator returned points an element which points to the position after the last element in the container.

Syntax:

`multiset_name.upper_bound(key)`

Parameters: This function accepts a single mandatory parameter key that specifies the element whose upper_bound is to be returned.

Return Value: The function returns an iterator.

Below programs illustrate the above function:

Program 1:

## C++

 `// C++ program to demonstrate the``// multiset::upper_bound() function``#include ``using` `namespace` `std;``int` `main()``{` `    ``multiset<``int``> s;` `    ``// Function to insert elements``    ``// in the multiset container``    ``s.insert(1);``    ``s.insert(3);``    ``s.insert(3);``    ``s.insert(5);``    ``s.insert(4);` `    ``cout << ``"The multiset elements are: "``;``    ``for` `(``auto` `it = s.begin(); it != s.end(); it++)``        ``cout << *it << ``" "``;` `    ``// when 3 is present``    ``auto` `it = s.upper_bound(3);``    ``cout << ``"\nThe upper bound of key 3 is "``;``    ``cout << (*it) << endl;` `    ``// when 2 is not present``    ``// points to next greater after 2``    ``it = s.upper_bound(2);``    ``cout << ``"The upper bound of key 2 is "``;``    ``cout << (*it) << endl;` `    ``// when 10 exceeds the max element in multiset``    ``it = s.upper_bound(10);``    ``cout << ``"The upper bound of key 10 is "``;``    ``cout << (*it) << endl;` `    ``return` `0;``}`

Output:

```The multiset elements are: 1 3 3 4 5
The upper bound of key 3 is 4
The upper bound of key 2 is 3
The upper bound of key 10 is 5```

Program 2:

## C++

 `// C++ program to demonstrate the``// multiset::upper_bound() function``#include ``using` `namespace` `std;``int` `main()``{` `    ``multiset<``int``> s;` `    ``// Function to insert elements``    ``// in the multiset container``    ``s.insert(10);``    ``s.insert(13);``    ``s.insert(13);``    ``s.insert(25);``    ``s.insert(24);` `    ``cout << ``"The multiset elements are: "``;``    ``for` `(``auto` `it = s.begin(); it != s.end(); it++)``        ``cout << *it << ``" "``;` `    ``// when 10 is present``    ``auto` `it = s.upper_bound(10);``    ``cout << ``"\nThe upper bound of key 10 is "``;``    ``cout << (*it) << endl;` `    ``// when 2 is not present``    ``// points to next greater after 2``    ``it = s.upper_bound(2);``    ``cout << ``"The upper bound of key 2 is "``;``    ``cout << (*it) << endl;` `    ``// when 24 exceeds is the max element``    ``it = s.upper_bound(24);``    ``cout << ``"The upper bound of key 24 is "``;``    ``cout << (*it) << endl;` `    ``return` `0;``}`

Output

```The multiset elements are: 10 13 13 24 25
The upper bound of key 10 is 13
The upper bound of key 2 is 10
The upper bound of key 24 is 25```

All functions of multiset

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