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# nlohmann::basic_json::end_pos
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```
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#if JSON_DIAGNOSTIC_POSITIONS
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constexpr std::size_t end_pos() const noexcept;
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#endif
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```
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Returns the position immediately following the last character of the JSON string from which the value was parsed from.
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| JSON type | return value |
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| --------- | --------------------------------- |
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| object | position after the closing `}` |
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| array | position after the closing `]` |
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| string | position after the closing `"` |
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| number | position after the last character |
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| boolean | position after `e` |
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| null | position after `l` |
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## Return value
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the position of the character *following* the last character of the given value in the parsed JSON string, if the value was created by the [`parse`](https://json.nlohmann.me/api/basic_json/parse/index.md) function, or `std::string::npos` if the value was constructed otherwise
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## Exception safety
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No-throw guarantee: this member function never throws exceptions.
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## Complexity
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Constant.
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## Notes
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Note
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The function is only available if macro [`JSON_DIAGNOSTIC_POSITIONS`](https://json.nlohmann.me/api/macros/json_diagnostic_positions/index.md) has been defined to `1` before including the library header.
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Invalidation
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The returned positions are only valid as long as the JSON value is not changed. The positions are *not* updated when the JSON value is changed.
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## Examples
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Example
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```
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#include <iostream>
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#define JSON_DIAGNOSTIC_POSITIONS 1
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#include <nlohmann/json.hpp>
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using json = nlohmann::json;
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int main()
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{
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std::string json_string = R"(
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{
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"address": {
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"street": "Fake Street",
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"housenumber": 1
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}
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}
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)";
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json j = json::parse(json_string);
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std::cout << "Root diagnostic positions: \n";
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std::cout << "\tstart_pos: " << j.start_pos() << '\n';
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std::cout << "\tend_pos:" << j.end_pos() << "\n";
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std::cout << "Original string: \n";
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std::cout << "{\n \"address\": {\n \"street\": \"Fake Street\",\n \"housenumber\": 1\n }\n }" << "\n";
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std::cout << "Parsed string: \n";
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std::cout << json_string.substr(j.start_pos(), j.end_pos() - j.start_pos()) << "\n\n";
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std::cout << "address diagnostic positions: \n";
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std::cout << "\tstart_pos:" << j["address"].start_pos() << '\n';
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std::cout << "\tend_pos:" << j["address"].end_pos() << "\n\n";
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std::cout << "Original string: \n";
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std::cout << "{ \"street\": \"Fake Street\",\n \"housenumber\": 1\n }" << "\n";
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std::cout << "Parsed string: \n";
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std::cout << json_string.substr(j["address"].start_pos(), j["address"].end_pos() - j["address"].start_pos()) << "\n\n";
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std::cout << "street diagnostic positions: \n";
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std::cout << "\tstart_pos:" << j["address"]["street"].start_pos() << '\n';
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std::cout << "\tend_pos:" << j["address"]["street"].end_pos() << "\n\n";
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std::cout << "Original string: \n";
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std::cout << "\"Fake Street\"" << "\n";
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std::cout << "Parsed string: \n";
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std::cout << json_string.substr(j["address"]["street"].start_pos(), j["address"]["street"].end_pos() - j["address"]["street"].start_pos()) << "\n\n";
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std::cout << "housenumber diagnostic positions: \n";
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std::cout << "\tstart_pos:" << j["address"]["housenumber"].start_pos() << '\n';
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std::cout << "\tend_pos:" << j["address"]["housenumber"].end_pos() << "\n\n";
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std::cout << "Original string: \n";
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std::cout << "1" << "\n";
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std::cout << "Parsed string: \n";
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std::cout << json_string.substr(j["address"]["housenumber"].start_pos(), j["address"]["housenumber"].end_pos() - j["address"]["housenumber"].start_pos()) << "\n\n";
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}
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```
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Output:
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```
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Root diagnostic positions:
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start_pos: 5
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end_pos:109
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Original string:
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{
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"address": {
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"street": "Fake Street",
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"housenumber": 1
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}
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}
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Parsed string:
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{
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"address": {
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"street": "Fake Street",
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"housenumber": 1
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}
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}
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address diagnostic positions:
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start_pos:26
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end_pos:103
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Original string:
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{ "street": "Fake Street",
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"housenumber": 1
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}
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Parsed string:
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{
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"street": "Fake Street",
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"housenumber": 1
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}
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street diagnostic positions:
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start_pos:50
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end_pos:63
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Original string:
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"Fake Street"
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Parsed string:
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"Fake Street"
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housenumber diagnostic positions:
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start_pos:92
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end_pos:93
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Original string:
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1
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Parsed string:
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1
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```
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The output shows the start/end positions of all the objects and fields in the JSON string.
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## See also
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- [start_pos](https://json.nlohmann.me/api/basic_json/start_pos/index.md) to access the start position
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- [JSON_DIAGNOSTIC_POSITIONS](https://json.nlohmann.me/api/macros/json_diagnostic_positions/index.md) for an overview of the diagnostic positions
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## Version history
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- Added in version 3.12.0.
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