Dart Map manipulation value - flutter

Question

Dart Can't change map value from initial map
I have this code :
void main() {
Map tabtest = {
'1' : {
'd' : 'one'
}
};
Map tabtest1 = {};
tabtest.forEach((cle1, val1) {
val1['d']='two';
tabtest1['cle1']=val1;
});
Map tabtest2={};
tabtest.forEach((cle2, val2) {
val2['d']='three';
tabtest2['cle2']=val2;
});
print(tabtest);
print(tabtest1);
print(tabtest2);
}
This code display :
{1: {d: three}}
{1: {d: three}}
{1: {d: three}}
But I want different value from tabtest1 and tabtest2 like :
tabtest1 = {1: {d: two}}
tabtest2 = {1: {d: three}}
Can help me?
Thanks.

Answer 1

There were a couple of problems:
you were actually using the same sub-map {'d': 'one'} in all three versions, instead of creating three seperate maps. The easiest way to copy a Map is to use Map secondMap = Map.from(firstMap). Beware though - this will only copy the first 'level' of the map. See this question for more information
you were using the string 'cle1' instead of it's value, so tabtest1['cle1'] should have been tabtest1[cle1]
void main() {
Map tabtest = {
'1' : {
'd' : 'one'
}
};
Map tabtest1 = {};
// For each map entry in tabtest
tabtest.forEach((cle, val) {
// First COPY the sub-map. If we don't make a copy, we end up
// changing the sub-map in both tabtest and tabtest2
Map val1 = Map.from(val);
// Then we can update the value in our new sub-map:
val1['d']='two';
// And set this as the key '1' in tabtest1
tabtest1[cle]=val1;
});
Map tabtest2={};
tabtest.forEach((cle, val) {
Map val2 = Map.from(val);
val2['d']='three';
tabtest2[cle]=val2;
});
print(tabtest);
print(tabtest1);
print(tabtest2);
}
{1: {d: one}}
{1: {d: two}}
{1: {d: three}}