map<T> method
The current elements of this iterable modified by toElement
.
Returns a new lazy Iterable with elements that are created by
calling toElement
on each element of this Iterable
in
iteration order.
The returned iterable is lazy, so it won't iterate the elements of
this iterable until it is itself iterated, and then it will apply
toElement
to create one element at a time.
The converted elements are not cached.
Iterating multiple times over the returned Iterable
will invoke the supplied toElement
function once per element
for on each iteration.
Methods on the returned iterable are allowed to omit calling toElement
on any element where the result isn't needed.
For example, elementAt may call toElement
only once.
Equivalent to:
Iterable<T> map<T>(T toElement(E e)) sync* {
for (var value in this) {
yield toElement(value);
}
}
Example:
var products = jsonDecode('''
[
{"name": "Screwdriver", "price": 42.00},
{"name": "Wingnut", "price": 0.50}
]
''');
var values = products.map((product) => product['price'] as double);
var totalPrice = values.fold(0.0, (a, b) => a + b); // 42.5.
Implementation
@override
Iterable<T> map<T>(T Function(num e) f) => _items.map(f);