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doc/examples/count.cpp

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+#include <json.hpp>
+
+using namespace nlohmann;
+
+int main()
+{
+    // create a JSON object
+    json j_object = {{"one", 1}, {"two", 2}};
+
+    // call find
+    auto count_two = j_object.count("two");
+    auto count_three = j_object.count("three");
+
+    // print values
+    std::cout << std::boolalpha;
+    std::cout << "number of elements with key \"two\": " << count_two << '\n';
+    std::cout << "number of elements with key \"three\": " << count_three << '\n';
+}