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69 lines
1.5 KiB
Markdown
69 lines
1.5 KiB
Markdown
# <small>nlohmann::json_pointer::</small>back
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```cpp
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const string_t& back() const;
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```
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Return the last reference token.
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## Return value
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Last reference token.
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## Exception safety
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Strong exception safety: if an exception occurs, the original value stays intact.
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## Exceptions
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Throws [out_of_range.405](../../home/exceptions.md#jsonexceptionout_of_range405) if the JSON pointer has no parent.
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## Complexity
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Constant.
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## Examples
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??? example
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The example shows the usage of `back`.
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```cpp
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#include <iostream>
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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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// different JSON Pointers
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json::json_pointer ptr1("/foo");
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json::json_pointer ptr2("/foo/0");
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// call empty()
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std::cout << "last reference token of \"" << ptr1 << "\" is \"" << ptr1.back() << "\"\n"
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<< "last reference token of \"" << ptr2 << "\" is \"" << ptr2.back() << "\"" << std::endl;
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}
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```
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Output:
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```json
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last reference token of "/foo" is "foo"
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last reference token of "/foo/0" is "0"
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```
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## See also
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- [front](front.md) return first reference token
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- [pop_back](pop_back.md) remove the last reference token
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- [push_back](push_back.md) append an unescaped token at the end of the pointer
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- [parent_pointer](parent_pointer.md) returns the parent of this JSON pointer
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## Version history
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- Added in version 3.6.0.
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- Changed return type to `string_t` in version 3.11.0.
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