JSON for Modern C++  3.0
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = int64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator>
size_type nlohmann::basic_json::erase ( const typename object_t::key_type &  key)
inline

Removes elements from a JSON object with the key value key.

Parameters
[in]keyvalue of the elements to remove
Returns
Number of elements removed. If ObjectType is the default std::map type, the return value will always be 0 (key was not found) or 1 (key was found).
Exceptions
std::domain_errorwhen called on a type other than JSON object
Complexity
log(size()) + count(key)
Example
The example shows the effect of erase.
1 #include <json.hpp>
2 
3 using namespace nlohmann;
4 
5 int main()
6 {
7  // create a JSON object
8  json j_object = {{"one", 1}, {"two", 2}};
9 
10  // call erase
11  auto count_one = j_object.erase("one");
12  auto count_three = j_object.erase("three");
13 
14  // print values
15  std::cout << j_object << '\n';
16  std::cout << count_one << " " << count_three << '\n';
17 }
a class to store JSON values
Definition: json.hpp:130
namespace for Niels Lohmann
Definition: json.hpp:55
InteratorType erase(InteratorType pos)
remove element given an iterator
Definition: json.hpp:2831
Output (play with this example online):
{"two":2}
1 0
The example code above can be translated with
g++ -std=c++11 -Isrc doc/examples/erase__key_type.cpp -o erase__key_type