Sort list flutter

Question

I'm looking for a simplest way to sort list based on given value instead of using two list.

Example I have list [a,b,c,d], with a given value d,I can sort it like this:

But if I have an object list, how can I sort it based on given value?

Example

List<ABC> list = [{fid:1,name:"a"},{fid:2,name:"b"},{fid:3,name:"c"},{fid:4,name:"d"}]

I have value 3. I want to sort the list become

List<ABC> list = [{fid:3,name:"c"},{fid:1,name:"A"},{fid:2,name:"b"},{fid:4,name:"d"},{fid:4,name:"d"}]

Solution 1

You just need to perform custom sorting here, rest of the things will remain same.

  List list = [{"fid":1,"name":"z"},{"fid":10,"name":"b"},{"fid":5,"name":"c"},{"fid":4,"name":"d"}];
  
  list.sort((a,b)=> a["fid"].compareTo(b["fid"]));
  
  int fidIndex=4;
  
  int indexToRemove=list.indexWhere((element) => element["fid"]==fidIndex);

  Map<String,dynamic> removedItem= list.removeAt(indexToRemove);

  list.insert(0,removedItem); 

  print(list);

Solution 2

You can sort list using comparator:

const list = [{fid:1,name:"a"},{fid:2,name:"b"},{fid:3,name:"c"},{fid:4,name:"d"}]
const fixedFid = 3

const sortedList = list.sort( (item1, item2) => { 
    if (item1.fid === fixedFid){
        return -1
    }
    if (item2.fid == fixedFid){
        return 1
    }
    return item1.fid.localeCompare(item2.fid)
})

Comments

[pskink]

so what sort order do you want to have? the two lists you posted are completly different lists

[John Joe]

@pskink I want to sort it based on a given fid.

[pskink]

you already got an answer: list.sort((a,b)=> a["fid"].compareTo(b["fid"]));

[John Joe]

But what if I only given a fid?

[John Joe]

But what if I only given a fid?

[Alexander Karp]

@JohnJoe You can create custom comparator and define rules according your fields, so instead of using name property you can use fid, I updated the code