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C++ Map Library - operator= Function
Description
The C++ function std::map::operator= assign new contents to the map by replacing old ones and modifies size if necessary.
Declaration
Following is the declaration for std::map::operator= function form std::map header.
C++98
map& operator= (const map& x);
C++11
map& operator= (const map& x);
Parameters
x − Another map object of same type
Return value
Returns this pointer
Exceptions
This member function doesn't throw exception.
Time complexity
Linear i.e. O(n)
Example
The following example shows the usage of std::map::operator= function.
#include <iostream> #include <map> using namespace std; int main(void) { /* Initializer_list constructor */ map<char, int> m1 = { {'a', 1}, {'b', 2}, {'c', 3}, {'d', 4}, {'e', 5}, }; map<char, int> m2 = m1; cout << "Map contains following elements" << endl; for (auto it = m2.begin(); it != m2.end(); ++it) cout << it->first << " = " << it->second << endl; return 0; }
Let us compile and run the above program, this will produce the following result −
Map contains following elements a = 1 b = 2 c = 3 d = 4 e = 5
map.htm
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