support map.size(),map.clear(),for(var k in map)

[liuzhangjie]

in smart contract,in fact,there are no methods to get the size of map,take visit to a map and delete some elements in a map.so I wish something better can occur to solve these problems.

[royshang]

Good Suggestion. Map iterator has been included in our Go-Nebulas V1.1.0. This version will be released at the middle of May, 2018.

[ChengOrangeJu]

@liuzhangjie Could you help update the status of this issue? Thanks!

[liuzhangjie]

add a counter k-counter,initial k-counter = 0
use two maps indexMap and dataMap,as you want to use set/put method to storage the k-v,you can do like this:first indexMap.put(k-counter,key);k-counter += 1; then dataMap.put(key,value);
after you use this way to storage the k-v,you can easily get the size of the map,that is the k-counter,and use : for(var i=0;i<k-counter;i++){
var k = indexMap.get(i);
var data = dataMap.get(k);
}
to iterate the map.Also,you can use this way to clear the map