The unordered_multimap::swap() is a built-in function in C++ STL which swaps the contents of two unordered_multimap containers. The sizes can differ of both the containers.
Syntax:
unordered_multimap_name1.swap(unordered_multimap_name2)
Parameters: The function accepts a single mandatory parameter unordered_multimap_name2 which specifies the unordered_multimap with which the swapping of unordered_multimap_name1 is to be done.
Return Value: It does not return anything.
Below programs illustrates the above function:
Program 1:
// C++ program to illustrate the // unordered_multimap::swap() #include <bits/stdc++.h> using namespace std;
int main()
{ // declaration
unordered_multimap< int , int > sample1, sample2;
// inserts key and element
// in sample1
sample1.insert({ 10, 100 });
sample1.insert({ 50, 500 });
// inserts key and element
// in sample1
sample2.insert({ 20, 200 });
sample2.insert({ 30, 300 });
sample2.insert({ 30, 150 });
cout << "Key and Elements of Sample1 before swap are:" ;
for ( auto it = sample1.begin(); it != sample1.end(); it++) {
cout << "{" << it->first << ", " << it->second << "} " ;
}
cout << "\nKey and Elements of Sample2 before swap are:" ;
for ( auto it = sample2.begin(); it != sample2.end(); it++) {
cout << "{" << it->first << ", " << it->second << "} " ;
}
// performs swap of two
// unordered_multimaps
sample1.swap(sample2);
cout << "\n\nKey and Elements of Sample1 after swap are:" ;
for ( auto it = sample1.begin(); it != sample1.end(); it++) {
cout << "{" << it->first << ", " << it->second << "} " ;
}
cout << "\nKey and Elements of Sample2 after swap are:" ;
for ( auto it = sample2.begin(); it != sample2.end(); it++) {
cout << "{" << it->first << ", " << it->second << "} " ;
}
return 0;
} |
Output:
Key and Elements of Sample1 before swap are:{50, 500} {10, 100} Key and Elements of Sample2 before swap are:{20, 200} {30, 150} {30, 300} Key and Elements of Sample1 after swap are:{20, 200} {30, 150} {30, 300} Key and Elements of Sample2 after swap are:{50, 500} {10, 100}
Program 2:
// C++ program to illustrate the // unordered_multimap::swap() #include <bits/stdc++.h> using namespace std;
int main()
{ // declaration
unordered_multimap< char , char > sample1, sample2;
// inserts key and element
// in sample1
sample1.insert({ 'a' , 'A' });
sample1.insert({ 'g' , 'G' });
// inserts key and element
// in sample1
sample2.insert({ 'b' , 'B' });
sample2.insert({ 'c' , 'C' });
sample2.insert({ 'd' , 'D' });
cout << "Key and Elements of Sample1 before swap are:" ;
for ( auto it = sample1.begin(); it != sample1.end(); it++) {
cout << "{" << it->first << ", " << it->second << "} " ;
}
cout << "\nKey and Elements of Sample2 before swap are:" ;
for ( auto it = sample2.begin(); it != sample2.end(); it++) {
cout << "{" << it->first << ", " << it->second << "} " ;
}
// performs swap of two
// unordered_multimaps
sample1.swap(sample2);
cout << "\n\nKey and Elements of Sample1 after swap are:" ;
for ( auto it = sample1.begin(); it != sample1.end(); it++) {
cout << "{" << it->first << ", " << it->second << "} " ;
}
cout << "\nKey and Elements of Sample2 after swap are:" ;
for ( auto it = sample2.begin(); it != sample2.end(); it++) {
cout << "{" << it->first << ", " << it->second << "} " ;
}
return 0;
} |
Output:
Key and Elements of Sample1 before swap are:{g, G} {a, A} Key and Elements of Sample2 before swap are:{d, D} {b, B} {c, C} Key and Elements of Sample1 after swap are:{d, D} {b, B} {c, C} Key and Elements of Sample2 after swap are:{g, G} {a, A}