Question

How to create and use unordered_map container for string and float in C++

Answer 1

#include <iostream>
#include <unordered_map>
#include <string>

int main()
{
	std::unordered_map<std::string, float> u_map;

	u_map["jp"] = 0.13;
	u_map["pi"] = 3.14;

	std::cout << "result: " << u_map["jp"] * u_map["pi"] << std::endl;

	return 0;
}

/*
run:

result: 0.4082

*/

 

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Answer 2

#include <iostream>
#include <unordered_map>
#include <string>

int main()
{
	std::unordered_map<std::string, float> u_map{ { "jp", 0.15 }, { "pi", 3.14 } };

	std::cout << "result: " << u_map["jp"] * u_map["pi"] << std::endl;

	return 0;
}

/*
run:

result: 0.471

*/

 

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Answer 3

#include <iostream>
#include <unordered_map>
#include <string>

int main()
{
	std::unordered_map<std::string, float> u_map{ { "jp", 0.15 }, { "pi", 3.14 } };

	for (const auto& elem : u_map) {
		std::cout << elem.first << ": " << elem.second << std::endl;
	}

	return 0;
}

/*
run:

jp: 0.15
pi: 3.14

*/

 

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