Map
main() {
var gifts = {
// Key: Value
'first': 'partridge',
'second': 'turtledoves',
'fifth': 'golden rings'
};
var nobleGases = {
2: '氦',
10: '氖',
18: '氩',
};
print(gifts);
print(nobleGases);
var mySites=new Map();
mySites['rsywx']=['rsywx.net','任氏有无轩'];
mySites['wiki']=['rsywx.com','维基站点'];
print(mySites);
nobleGases[36]='氪';
print(nobleGases);
nobleGases[36]='Assignment to an exisitng key will override the original value';
print(nobleGases);
}