JSON with jsonlite in R Programming

Introduction

JSON is a simple way to store and share data. The jsonlite package helps R talk with JSON easily.

You want to save R data so other programs can read it.

You receive data from a website or app in JSON format.

You want to send R data to a web service or API.

You want to read JSON files into R for analysis.

Syntax

R Programming

library(jsonlite)

# Convert R object to JSON
json_data <- toJSON(object)

# Convert JSON string to R object
r_object <- fromJSON(json_data)

Use toJSON() to turn R data into JSON text.

Use fromJSON() to read JSON text back into R data.

Examples

This turns a simple number list into JSON format.

R Programming

library(jsonlite)

# Convert a vector to JSON
vec <- c(10, 20, 30)
json_vec <- toJSON(vec)
print(json_vec)

This reads a JSON string of people into an R data frame.

R Programming

library(jsonlite)

# Convert JSON string to R list
json_str <- '[{"name":"Anna","age":25},{"name":"Bob","age":30}]'
r_list <- fromJSON(json_str)
print(r_list)

Sample Program

This program shows how to convert an R list to JSON and back. The pretty = TRUE option makes JSON easier to read.

R Programming

library(jsonlite)

# Create a simple R list
person <- list(name = "John", age = 28, city = "Paris")

# Convert to JSON
json_person <- toJSON(person, pretty = TRUE)
print(json_person)

# Convert JSON back to R object
r_person <- fromJSON(json_person)
print(r_person)

Important Notes

JSON text is always a string, so use toJSON() and fromJSON() to switch between R data and JSON text.

The pretty = TRUE option in toJSON() adds spaces and new lines to make JSON easier to read.

JSON keys are always strings, so R named list elements become JSON keys.

Summary

jsonlite helps R work with JSON data easily.

Use toJSON() to convert R data to JSON text.

Use fromJSON() to read JSON text back into R data.