Recursively parse an array of json objs

[ghost]

Hi!

I was just testing the library for the first time and couldn't find a way to parse something like the following:

{"people": [ {"name":"Alice", "age": 40}, {"name": "John", "age": 38} ]}

Is there a (optimal) way to do it?
Can you please provide an example on how to just iterate over multiple objs inside the array and print the "name" and "age"?

Thank you in advance!

[ibireme]

Try this:

const char *str = "{\"people\": [ {\"name\":\"Alice\", \"age\": 40}, {\"name\": \"John\", \"age\": 38} ]}";
yyjson_doc *doc = yyjson_read(str, strlen(str), 0);
yyjson_val *root = yyjson_doc_get_root(doc);
yyjson_val *people_arr = yyjson_obj_get(root, "people");

yyjson_arr_iter people_iter;
yyjson_arr_iter_init(people_arr, &people_iter);
yyjson_val *one;
while ((one = yyjson_arr_iter_next(&people_iter))) {
    printf("------\n");
    printf("name: %s\n", yyjson_get_str(yyjson_obj_get(one, "name")));
    printf("age:  %d\n", yyjson_get_int(yyjson_obj_get(one, "age")));
}

yyjson_doc_free(doc);

Maybe I should add more sample code.

[ghost]

Thank you!

Just one follow-up question, does your library provide any function to make the conversion from:

{"people": [ {"name":"Alice", "age": 40}, {"name": "John", "age": 38} ]}

To:

"{\"people\": [ {\"name\":\"Alice\", \"age\": 40}, {\"name\": \"John\", \"age\": 38} ]}"

as the data that I am working with (from files and web requests) appears to be in the former form.

Thank you once again for your help!

[ghost]

Second (and last) follow-up question.

On the previous example, assume that "age" can either be an integer or a float.
I have tried

yyjson_get_real(yyjson_obj_get(one, "age")
and it only works if it is a floating point and returns zero if age is an integer.

Now assume that you would always want to store "age" as a float/double, would it be necessary to check both functions yyjson_get_real, yyjson_get_int, and convert the result of the latter to (double) or is it possible to parse directly to double, even if the value is an int?

Thank you. :)

[ibireme]

1. "{\"people":...}" is an escaped c string literal for c source code: https://en.wikipedia.org/wiki/Escape_sequences_in_C
   If you have the original JSON data, just pass it directly to yyjson.

2. If the type of a value is unknown, you should check the type before:
   double num = yyjson_is_int(val) ? yyjson_get_int(val) : yyjson_get_real(val);

[ghost]

Fantastic.
Thank you very much for the support.
Please feel free to close this issue.