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### jsoncons::jsonpointer::replace
```cpp
#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>
template <typename Json,typename T>
void replace(Json& target,
const basic_json_pointer<Json::char_type>& location,
T&& value,
bool create_if_missing = false); (1)
template <typename Json,typename T>
void replace(Json& target,
const basic_json_pointer<Json::char_type>& location,
T&& value,
std::error_code& ec); (2)
template <typename Json,typename T>
void replace(Json& target,
const basic_json_pointer<Json::char_type>& location,
T&& value,
bool create_if_missing,
std::error_code& ec); (3)
template <typename Json,typename StringSource,typename T>
void replace(Json& target,
const StringSource& location_str,
T&& value,
bool create_if_missing = false); (4)
template <typename Json,typename StringSource,typename T>
void replace(Json& target,
const StringSource& location_str,
T&& value,
std::error_code& ec); (5)
template <typename Json,typename StringSource,typename T>
void replace(Json& target,
const StringSource& location_str,
T&& value,
bool create_if_missing,
std::error_code& ec); (6)
```
Replaces the value at the location specified by `location` with a new value.
If `create_if_missing` is `false`, the target location must exist
for the replacement to succeed. If `create_if_missing` is `true`,
and if the target location specifies object members that do not
already exist, the missing objects and members are added.
#### Parameters
<table>
<tr>
<td>target</td>
<td>JSON value</td>
</tr>
<tr>
<td>location</td>
<td>A <a href="basic_json_pointer.md">basic_json_pointer</a></td>
</tr>
<tr>
<td>location_str</td>
<td>A JSON Pointer provided as a string, string view, or C-string</td>
</tr>
<tr>
<td>value</td>
<td>Replacement value</td>
</tr>
<tr>
<td><code>create_if_missing</code> (since 0.162.0)</td>
<td>Create key-object pairs when object key is missing</td>
</tr>
<tr>
<td><code>ec</code></td>
<td>out-parameter for reporting errors in the non-throwing overload</td>
</tr>
</table>
#### Return value
None
#### Exceptions
(1) Throws a [jsonpointer_error](jsonpointer_error.md) if `replace` fails.
(2) Sets the out-parameter `ec` to the [jsonpointer_error_category](jsonpointer_errc.md) if `replace` fails.
### Examples
#### Replace an object value
```cpp
#include <jsoncons/json.hpp>
#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>
using jsoncons::json;
namespace jsonpointer = jsoncons::jsonpointer;
int main()
{
auto target = json::parse(R"(
{
"baz": "qux",
"foo": "bar"
}
)");
std::error_code ec;
jsonpointer::replace(target, "/baz", json("boo"), ec);
if (ec)
{
std::cout << ec.message() << '\n';
}
else
{
std::cout << target << '\n';
}
}
```
Output:
```json
{
"baz": "boo",
"foo": "bar"
}
```
#### Replace an array value
```cpp
#include <jsoncons/json.hpp>
#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>
using jsoncons::json;
namespace jsonpointer = jsoncons::jsonpointer;
int main()
{
auto target = json::parse(R"(
{ "foo": [ "bar", "baz" ] }
)");
std::error_code ec;
jsonpointer::replace(target, "/foo/1", json("qux"), ec);
if (ec)
{
std::cout << ec.message() << '\n';
}
else
{
std::cout << pretty_print(target) << '\n';
}
}
```
Output:
```json
{
"foo": ["bar","qux"]
}
```
#### Replace a value at a location after creating objects when missing object keys
```cpp
#include <iostream>
#include <jsoncons/json.hpp>
#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>
using jsoncons::json;
namespace jsonpointer = jsoncons::jsonpointer;
int main()
{
std::vector<std::string> keys = {"foo","bar","baz"};
jsonpointer::json_pointer location;
for (const auto& key : keys)
{
location /= key;
}
json doc;
jsonpointer::replace(doc, location, "str", true);
std::cout << pretty_print(doc) << "\n\n";
}
```
Output:
```json
{
"foo": {
"bar": {
"baz": "str"
}
}
}
```
|
