I want to reverse the key and value of Map-CodePudding

How can I reverse the key and value of the map?

for example, {1:a , 2:b , 3:c} => {a:1 ,b:2 ,c:3}

CodePudding user response：

You can do this:

const items = {1:'a' , 2:'b' , 3:'c'};

void main() {
  final inverted = items.map((key, value) => MapEntry(value, key));
  print(inverted);
}

It logs

{a: 1, b: 2, c: 3}

CodePudding user response：

Try this piece of code:

Map<int, String> map = {1: "a", 2: "b", 3: "c"};

  Iterable<String> values = map.values;
  Iterable<int> keys = map.keys;
  Map<String, int> reversedMap = Map.fromIterables(values, keys);

  print(reversedMap); // {a:1 ,b:2 ,c:3}

CodePudding user response：

Try this example. As simple as efficient.

var obj = {1:'x',2:'y',3:'z'};
var newObj = {};
for(let o in obj){
  newObj[obj[o]] = o;
}
console.log(newObj)

Please do let me know thoughts on this.