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### contains
```
boolean contains(array|string source, any search)
```
If source is an array, returns true if the array contains an item that is equal to
the search value, false otherwise.
If source is a string, returns true if the string contains a substring that is equal to
the search value, false otherwise.
It is a type error if
- the provided source is not an array or string, or
- the provided source is a string but the provided search value is not a string.
### Examples
```cpp
#include <iostream>
#include <jsoncons/json.hpp>
#include <jsoncons_ext/jsonpath/jsonpath.hpp>
// for brevity
using jsoncons::json;
namespace jsonpath = jsoncons::jsonpath;
int main()
{
std::string data = R"(
{
"books":
[
{
"title" : "A Wild Sheep Chase",
"author" : "Haruki Murakami",
"price" : 22.72
},
{
"title" : "The Night Watch",
"author" : "Sergei Lukyanenko",
"price" : 23.58
},
{
"title" : "The Comedians",
"author" : "Graham Greene",
"price" : 21.99
},
{
"title" : "The Night Watch",
"author" : "Phillips, David Atlee"
}
]
}
)";
json j = json::parse(data);
// All books that don't have a price
std::string expr = "$.books[?(!contains(keys(@),'price'))]";
json result = jsonpath::json_query(j, expr);
std::cout << result << "\n\n";
}
```
Output:
```
[{"author":"Phillips, David Atlee","title":"The Night Watch"}]
```
|
