convert list to array in R-CodePudding

I am putting some results together in a nested list (with arrays). The expected results must be EXACTLY as follows:

{
 "item1": "TEXT",
 "item2": "MORE TEXT",
 "item3": [
  "STILL TEXT"
 ],
 "item4": [
  "TEXT AGAIN"
 ],
 "values": [
  {
   "start": 0,
   "end": 99
  }
 ]
}

I put all my results together like this:

listToJson <- c(list(item1 = "TEXT", 
                     item2 = "MORE TEXT", 
                     item3 = "STILL TEXT", 
                     item4  = "TEXT AGAIN", 
                     values = list(start = 99, 
                                   end = 0)))

write_json(listToJson, path = "test.json", auto_unbox = TRUE , null = "null")

The problem is that the results doesn't have array elements (see below). item3 and item4 should be arrays. How can I change my code to get the expected results in that exact format?

{
 "item1":"TEXT",
 "item2":"MORE TEXT",
 "item3":"STILL TEXT",
 "item4":"TEXT AGAIN",
 "values":{
  "start":99,
  "end":0}
 }

CodePudding user response：

You can just use as.array for those specific items.

library(jsonlite)

listToJson <- c(
  list(
    item1 = "TEXT",
    item2 = "MORE TEXT",
    item3 = as.array("STILL TEXT"),
    item4  = as.array("TEXT AGAIN"),
    values = as.array(list(start = 99,
                           end = 0))
  )
)

write_json(listToJson, path = "test.json", auto_unbox = TRUE , null = "null")

Output

{
  "item1":"TEXT",
  "item2":"MORE TEXT",
  "item3":[
    "STILL TEXT"
  ],
  "item4":[
    "TEXT AGAIN"
  ],
  "values":[
    {
      "start":0,
      "end":99
    }
  ]
}