:sig
bool DValue::has(String s) const

:params
s : child key to test
return value : true when the dereferenced value is map-shaped and contains the key

:see
>types
0_DValue
2_DValue_key
2_DValue_get_by_path

:content
Checks for a child key without creating it. Returns false for scalars and missing keys.

:example
DValue user;
user["name"] = "Ada";
print(user.has("name") ? "yes\n" : "no\n");
