1# <small>nlohmann::basic_json::</small>size 2 3```cpp 4size_type size() const noexcept; 5``` 6 7Returns the number of elements in a JSON value. 8 9## Return value 10 11The return value depends on the different types and is defined as follows: 12 13| Value type | return value | 14|------------|-------------------------------------| 15| null | `0` | 16| boolean | `1` | 17| string | `1` | 18| number | `1` | 19| binary | `1` | 20| object | result of function object_t::size() | 21| array | result of function array_t::size() | 22 23## Exception safety 24 25No-throw guarantee: this function never throws exceptions. 26 27## Complexity 28 29Constant, as long as [`array_t`](array_t.md) and [`object_t`](object_t.md) satisfy the 30[Container](https://en.cppreference.com/w/cpp/named_req/Container) concept; that is, their `size()` functions have 31constant complexity. 32 33## Notes 34 35This function does not return the length of a string stored as JSON value -- it returns the number of elements in the 36JSON value which is `1` in the case of a string. 37 38## Examples 39 40??? example 41 42 The following code calls `size()` on the different value types. 43 44 ```cpp 45 --8<-- "examples/size.cpp" 46 ``` 47 48 Output: 49 50 ```json 51 --8<-- "examples/size.output" 52 ``` 53 54## Version history 55 56- Added in version 1.0.0. 57- Extended to return `1` for binary types in version 3.8.0. 58