The unordered_multimap::clear() is a built-in function in C++ STL which clears the contents of the unordered_multimap container. The final size of the container after the call of the function is 0.
Syntax:
unordered_multimap_name.clear()
Parameters: The function does not accept any parameter.
Return Value: It returns nothing.
Below programs illustrates the above function:
Program 1:
// C++ program to illustrate the // unordered_multimap::clear() #include <bits/stdc++.h> using namespace std;
int main()
{ // declaration
unordered_multimap< int , int > sample;
// inserts key an delement
sample.insert({ 10, 100 });
sample.insert({ 10, 100 });
sample.insert({ 20, 200 });
sample.insert({ 30, 300 });
sample.insert({ 15, 150 });
cout << "Key and Elements of multimap are:" ;
for ( auto it = sample.begin(); it != sample.end(); it++) {
cout << "\n{" << it->first << ", " << it->second << "}" ;
}
sample.clear();
cout << "\nSize of container after function call: "
<< sample.size();
return 0;
} |
Output:
Key and Elements of multimap are: {15, 150} {30, 300} {20, 200} {10, 100} {10, 100} Size of container after function call: 0
Program 2:
// C++ program to illustrate the // unordered_multimap::clear() #include <bits/stdc++.h> using namespace std;
int main()
{ // declaration
unordered_multimap< char , char > sample;
// inserts element
sample.insert({ 'a' , 'b' });
sample.insert({ 'a' , 'b' });
sample.insert({ 'b' , 'c' });
sample.insert({ 'r' , 'a' });
sample.insert({ 'c' , 'b' });
cout << "Key and Elements of multimap are:" ;
for ( auto it = sample.begin(); it != sample.end(); it++) {
cout << "\n{" << it->first << ", " << it->second << "}" ;
}
sample.clear();
cout << "\nSize of container after function call: "
<< sample.size();
return 0;
} |
Output:
Key and Elements of multimap are: {c, b} {r, a} {b, c} {a, b} {a, b} Size of container after function call: 0