How to Parse an Array of Objects in C++ Using RapidJson?

We will learn how to parse an array of objects in this part.

RapidJSON is a free and open-source C++ library for parsing and serialising JSON data. It is intended to be quick and efficient, with an emphasis on straightforwardness and ease of use. It is widely used in a variety of purposes and is noted for its high efficiency and low environmental impact. It is a common alternative in C++ for parsing and serialising JSON data.

RapidJSON's features include:

  • A simple, user-friendly API for parsing and serialising JSON data.
  • Dynamic memory access and memory management are supported.
  • Support is available for the SAX and DOM parsing styles for XML documents.
  • JSON data parsing from strings, streams, and files is supported.
  • Support for a wide range of fundamental data types, such as numbers, strings, arrays, and objects.
  • JSON data serialisation to strings, streams, and files is supported.
  • RapidJSON's features also includes the reading and writing JSON data with and without any formatting is supported (e.g., indentation and whitespace).

Install the RapidJSON library:

  1. Go to this URL to obtain RapidJSON's most recent version from GitHub. The source code can be downloaded as a zip file, or you can clone the repository with Git.
  2. Unzip the installed zip file or browse to the cloned repository's root directory.
  3. Because RapidJSON is a header-only library, users are not required to create or connect it to their projects. We only must include the relevant header files in our C++ code. The RapidJSON repository's directory contains the header files.
  4. We must include the relevant header files in our C++ code to utilise RapidJSON. We can accomplish this by include the following words in our C++ code:
  5. If users wish to utilise RapidJSON in many files in their project, add the include directory of the RapidJSON repository to each project's include path. In the same way, users can also include the RapidJSON header files in their code by using double quotes (") rather than angle brackets (<>).

Using the RapidJSON library to parse JSON stringified data

Throughout the below code, we build a JSON string and then parse it with the rapidjson::Document class's Parse() method. The HasParseError() method is then used to check for parse issues. If there are no parsing problems, we can use the [] operator to get the data from the JSON document and the rapidjson::Value class (e.g., GetString(), GetInt() and so on).

C++ Program:

Output:

Name: Priya
Age: 21
City: Kolkata

Using RapidJson to Parse an Array of Objects in C++

Let us divide these difficulties into the following steps:

  • Create a JSON string including an array of objects and parse it with the rapidjson::Document class's Parse() method.
  • You can check for parse issues by using the HasParseError() function. If you notice any parse issues, treat them appropriately.
  • Iterate through the array of objects using the rapidjson::Value class's Begin() and End() methods.
  • Access the data for each object using the [] operator and the rapidjson::Value class (e.g., GetString(), GetInt(), and so on.).

C++ Program:

Output:

Name: Sweta
Age: 19
City: Bihar
Name: Tina Bhatiya
Age: 18
City: Uttar Pradesh

RapidJSON has a plethora of additional tools and choices for parsing and processing JSON data. More information and examples can be found in the records and demonstrations included with the RapidJSON library.






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