# basic_json::array_t ```cpp using array_t = ArrayType>; ``` The type used to store JSON arrays. [RFC 7159](http://rfc7159.net/rfc7159) describes JSON arrays as follows: > An array is an ordered sequence of zero or more values. To store objects in C++, a type is defined by the template parameters explained below. ## Template parameters `ArrayType` : container type to store arrays (e.g., `std::vector` or `std::list`) `AllocatorType` : the allocator to use for objects (e.g., `std::allocator`) ## Notes #### Default type With the default values for `ArrayType` (`std::vector`) and `AllocatorType` (`std::allocator`), the default value for `array_t` is: ```cpp std::vector< basic_json, // value_type std::allocator // allocator_type > ``` #### Limits [RFC 7159](http://rfc7159.net/rfc7159) specifies: > An implementation may set limits on the maximum depth of nesting. In this class, the array's limit of nesting is not explicitly constrained. However, a maximum depth of nesting may be introduced by the compiler or runtime environment. A theoretical limit can be queried by calling the [`max_size`](max_size.md) function of a JSON array. #### Storage Arrays are stored as pointers in a `basic_json` type. That is, for any access to array values, a pointer of type `#!cpp array_t*` must be dereferenced. ## Version history - Added in version 1.0.0.