json/doc/mkdocs/docs/api/basic_json/dump.md

# basic_json::dump

```cpp
string_t dump(const int indent = -1,
              const char indent_char = ' ',
              const bool ensure_ascii = false,
              const error_handler_t error_handler = error_handler_t::strict) const
```

Serialization function for JSON values. The function tries to mimic
Python's `json.dumps()` function, and currently supports its `indent`
and `ensure_ascii` parameters.
    
## Parameters

`indent` (in)
:   If `indent` is nonnegative, then array elements and object
    members will be pretty-printed with that indent level. An indent level of
    `0` will only insert newlines. `-1` (the default) selects the most compact
    representation.

`indent_char` (in)
:   The character to use for indentation if `indent` is
    greater than `0`. The default is ` ` (space).

`ensure_ascii` (in)
:   If `ensure_ascii` is true, all non-ASCII characters
    in the output are escaped with `\uXXXX` sequences, and the result consists
    of ASCII characters only.

`error_handler` (in)
:   how to react on decoding errors; there are three
    possible values: `strict` (throws and exception in case a decoding error
    occurs; default), `replace` (replace invalid UTF-8 sequences with U+FFFD),
    and `ignore` (ignore invalid UTF-8 sequences during serialization; all
    bytes are copied to the output unchanged).
    
## Return value

string containing the serialization of the JSON value

## Exception safety

Strong guarantee: if an exception is thrown, there are no
changes to any JSON value.

## Complexity

Linear.

## Notes

Binary values are serialized as object containing two keys:

- "bytes": an array of bytes as integers
- "subtype": the subtype as integer or `#!json null` if the binary has no subtype

## Example

The following example shows the effect of different `indent`,
    `indent_char`, and `ensure_ascii` parameters to the result of the
    serialization.

```cpp
--8<-- "examples/dump.cpp"
```

Output:

```json
--8<-- "examples/dump.output"
```