JSON for Modern C++ 3.10.4

◆ basic_json() [6/10]

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 = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>
nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::basic_json ( size_type  cnt,
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType > &  val 
)
inline

Constructs a JSON array value by creating cnt copies of a passed value. In case cnt is 0, an empty array is created.

Parameters
[in]cntthe number of JSON copies of val to create
[in]valthe JSON value to copy
Postcondition
std::distance(begin(),end()) == cnt holds.
Complexity
Linear in cnt.
Exception safety
Strong guarantee: if an exception is thrown, there are no changes to any JSON value.
Example
The following code shows examples for the basic_json(size_type, const basic_json&) constructor.
1#include <iostream>
2#include <nlohmann/json.hpp>
3
4using json = nlohmann::json;
5
6int main()
7{
8 // create an array by creating copies of a JSON value
9 json value = "Hello";
10 json array_0 = json(0, value);
11 json array_1 = json(1, value);
12 json array_5 = json(5, value);
13
14 // serialize the JSON arrays
15 std::cout << array_0 << '\n';
16 std::cout << array_1 << '\n';
17 std::cout << array_5 << '\n';
18}
ValueType value(const typename object_t::key_type &key, const ValueType &default_value) const
access specified object element with default value
Definition: json.hpp:21500
basic_json<> json
default JSON class
Definition: json.hpp:3472

Output (play with this example online):
[]
["Hello"]
["Hello","Hello","Hello","Hello","Hello"]
The example code above can be translated with
g++ -std=c++11 -Isingle_include doc/examples/basic_json__size_type_basic_json.cpp -o basic_json__size_type_basic_json 
Since
version 1.0.0

Definition at line 19488 of file json.hpp.