I have a mapping that has values and I would like to iterate the map and display the results that satisfy the condition and return the results as the array. The function looks like this

fn iterate_map(&self) -> Vec<(AccountId, u32)> {
        let mut results = Vec::new();
        for (key, value) in self.my_map.iter() {
            if *value > 10 {
                results.push((*key, *value));

Now is it possible to do this action using ink smart contract?


1 Answer 1


Yeah mapping doesn't support iterating. You can insert value in mapping as well as Vec at same time like:

pub struct A {
  mapping: Mapping<id, value>,
  vector: Vec<id>,

later you can iterate vector and display those value. As for example I have included example you can go through this link

  • This is a good alternative except in cases where the mapping key is a string and the cost of storing it would be costly Commented Feb 17, 2023 at 15:23
  • yes if key is string then it may not be iterable
    – go11li
    Commented Feb 18, 2023 at 1:45

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