Finds an element in a JSON object with key equivalent to key. If the element is not found or the JSON value is not an object, end() is returned.
- Note
- This method always returns end() when executed on a JSON type that is not an object.
- Parameters
-
[in] | key | key value of the element to search for. |
- Returns
- Iterator to an element with key equivalent to key. If no such element is found or the JSON value is not an object, past-the-end (see end()) iterator is returned.
- Complexity
- Logarithmic in the size of the JSON object.
- Example
- The example shows how
find()
is used.
2 #include <nlohmann/json.hpp>
9 json j_object = {{
"one", 1}, {
"two", 2}};
12 auto it_two = j_object.find(
"two");
13 auto it_three = j_object.find(
"three");
16 std::cout << std::boolalpha;
17 std::cout <<
"\"two\" was found: " << (it_two != j_object.end()) <<
'\n';
18 std::cout <<
"value at key \"two\": " << *it_two <<
'\n';
19 std::cout <<
"\"three\" was found: " << (it_three != j_object.end()) <<
'\n';
Output (play with this example online): "two" was found: true
value at key "two": 2
"three" was found: false
The example code above can be translated withg++ -std=c++11 -Isingle_include doc/examples/find__key_type.cpp -o find__key_type
- See also
- contains(KeyT&&) const – checks whether a key exists
- Since
- version 1.0.0
Definition at line 18530 of file json.hpp.