Append/Add JsObject into JsArray in Play Framework

Question

I am newbie to Play Framework, I need to append/add JsObject elements into JsArray

Aim(What I need)

 {"s_no":1,"s_name":"one",
    ,"sub_s":  [{"sub_s_no":1,"sub_s_name":"one_sub","sub_s_desc":"one_sub"},{"sub_s_no":2,"sub_s_name":"two_sub","sub_s_desc":"two_sub"}]},
{"s_no":2,"s_name":"two","sub_s":[{"sub_s_no":2,"sub_s_name":"two_sub","sub_s_desc":"two_sub"},
    {"sub_s_no":3,"sub_s_name":"three_sub","sub_s_desc":"three_sub"}]}

What I Got

JsObject 1

{"s_no":1,"s_name":"one",
,"sub_s":[{"sub_s_no":1,"sub_s_name":"one_sub","sub_s_desc":"one_sub"},{"sub_s_no":2,"sub_s_name":"two_sub","sub_s_desc":"two_sub"}]}

JsObject 2

{"s_no":2,"s_name":"two","sub_s":[{"sub_s_no":2,"sub_s_name":"two_sub","sub_s_desc":"two_sub"},
{"sub_s_no":3,"sub_s_name":"three_sub","sub_s_desc":"three_sub"}]}

I have got two JsObject and will get more than two, I need to add/append these all JsObjects into JsArray

I tried with .+:,.append methods which gave empty JsArray values

Your "Aim" is not valid json. Also your JsObject 1 has an extra comma which means it also isn't valid json — JoseM
– JoseM, Commented Oct 14, 2015 at 19:12

JoseM · Accepted Answer · 2015-10-14 19:34:04Z

4

The reason why getting an empty JsArray is because JsArray is immutable so the original JsArray will not modified. You need to assign the result of the append to a new variable in order for it to work how you expect.

val jsonString1 = """{"s_no":1,"sub_s":[1,2]}"""
val jsonString2 = """{"s_no":2,"sub_s":[3,4]}"""

val jsObj1 = Json.parse(jsonString1)
val jsObj2 = Json.parse(jsonString2)

val emptyArray = Json.arr()
val filledArray = emptyArray :+ obj1 :+ obj2

Json.prettyPrint(emptyArray)
Json.prettyPrint(filledArray)

And some of the REPL output

> filledArray: play.api.libs.json.JsArray = [{"s_no":1,"s_name":"one","sub_s":[{"sub_s_no":1,"sub_s_name":"one_sub","sub_s_desc":"one_sub"},{"sub_s_no":2,"sub_s_name":"two_sub","sub_s_desc":"two_sub"}]},{"s_no":2,"s_name":"two","sub_s":[{"sub_s_no":2,"sub_s_name":"two_sub","sub_s_desc":"two_sub"},{"sub_s_no":3,"sub_s_name":"three_sub","sub_s_desc":"three_sub"}]}]
> // pretty print of the empty array
> res1: String = [ ]
> // pretty print of the filled array
> res2: String = [ {"s_no" : 1 ...}, {"s_no" : 2 ...} ]

edited Oct 14, 2015 at 19:34

answered Oct 14, 2015 at 19:25

JoseM

4,3022 gold badges26 silver badges35 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Jamal Over a year ago

JoseM, I am using for loop for getting a JsObjects as it may return any numbers based on my values. I used below code but it stores only the last JsObjects in filledArray. previous objects are not stored.

val emptyArray = Json.arr() var filledArray = emptyArray   for (testdata <- testList) {       val testObject:JsObject = Json.obj("s_no" -> testdata)	 	 filledArray = emptyArray :+ testObject              }     prinln("filledArray:="+filledArray)

Jamal Over a year ago

In for loop I used filledArray = filledArray :+ testObject instead of filledArray = emptyArray :+ testObject it solved my problem.Thanks friend.

JoseM Over a year ago

If you have an existing Seq of JsObjects you can just do JsArray(jsObjectsSeq). If you want to add it to an existing array you can do val updatedArray = existingArray ++ JsArray(jsObjectsSeq)

Collectives™ on Stack Overflow

Append/Add JsObject into JsArray in Play Framework

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related