How to check key value id exits or not in array of object in Flutter?

Question

How to check value is exits or not in an array of objects. Please give me a solution if it works then I accept your answer Anyone here with a solution for this? Thanks in Advance. Here is my code.

[{"index":0,"productId":"5d9890c7773be00ab5b41701","qty":2}, {"index":0,"productId":"5d9890c7773be00ab5b41701","qty":3}]

how to check ProductId is exited or not of this array in Flutter.

chunhunghan chunhunghan · Accepted Answer · 2019-11-14T08:07:35

Your List have duplicate value. In my demo, add an extra index 1 to prove it work
For unique and index only , use indexWhere
For return qualified list use where , firstWhere, singleWhere
You can see DarPad result
code snippet

void main()  {

 List<Map> productList = [{"index":0,"productId":"5d9890c7773be00ab5b41701","qty":2}, {"index":0,"productId":"5d9890c7773be00ab5b41701","qty":3},                   {"index":1,"productId":"5d9890c7773be00ab5b41702","qty":23}];

  int index = productList.indexWhere((prod) => prod["productId"]=='5d9890c7773be00ab5b41701' ); 
  print(index);

  var prodLists = productList.where((prod) => prod["productId"] == '5d9890c7773be00ab5b41701');

  print('${prodLists}');

}

Output

0
({index: 0, productId: 5d9890c7773be00ab5b41701, qty: 2}, {index: 0, productId: 5d9890c7773be00ab5b41701, qty: 3})

How to check key value id exits or not in array of object in Flutter?

1 Answers