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Automatic ordered JSON #424
Description
Hi,
Json is automatically sorted by an alphabetic order. I don't find any information about that in your readme. Is there a way to avoid sorting ?
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Hi,
Json is automatically sorted by an alphabetic order. I don't find any information about that in your readme. Is there a way to avoid sorting ?
Activity
gregmarr commentedon Jan 9, 2017
https://github.com/nlohmann/json/blob/master/.github/CONTRIBUTING.md
gregmarr commentedon Jan 9, 2017
#106
fyears commentedon Jan 12, 2017
Hi. A quick question regarding this issue (just out of curious): why not use std::unordered_map by default instead of std::map? After all, json objects are unsorted by semantics. And unordered_map should gain significant speed up regarding the time complexity.
nlohmann commentedon Jan 12, 2017
The problem is that we are defining an object
basic_jsonand inside a member of typestd::map<std::string, basic_json>. At this point,basic_jsonis not yet fully defined. This seems to be OK forstd::mapon all platforms/compilers I encountered so far, but it is not forstd::unordered_map.code-blooded245 commentedon Jan 20, 2020
Hi, is there any way to sort nlohmann::json depending upon values, like for example,
if key is string and value is double, can I sort json based on double?
nlohmann commentedon Jan 21, 2020
Can you give an example for this?
code-blooded245 commentedon Jan 22, 2020
Example:
if input = {
"abc" : 0.288,
"pqr" : 0.176,
"xyz" : 0.555,
"zaz" : 0.345
}
After sorting it should look something like,
output = {
"pqr" : 0.176,
"abc" : 0.288,
"lmo" : 0.345,
"xyz" : 0.555
}
Basically sorted by values.
nlohmann commentedon Jan 25, 2020
This is not possible in the library (see https://github.com/nlohmann/json#order-of-object-keys). You could parse the value into some C++ container (e.g., a vector of pairs) and sort it yourself.
code-blooded245 commentedon Jan 27, 2020
Thanks for the support.
code-blooded245 commentedon Jan 28, 2020
Hey, is there a way to use std::max_element with nlohmann::json to get the key-value pair with the highest value for the above-given example?
prototype:
auto max = std::max_element (j.begin(), j.end(), cmp);
nlohmann commentedon Feb 15, 2020
You may be able to achieve this via the
items()function.nlohmann commentedon Jul 11, 2020
To be fixed with #2258.