Flutter: Search inside the List - flutter

Question

I am trying to using the mobile_number plugin. Basically, I am fetching the SimCard number.
Here is the code.
String _mobileNumber = '';
List<SimCard> _simCard = <SimCard>[];
Future<void> initMobileNumberState() async {
if (!await MobileNumber.hasPhonePermission) {
await MobileNumber.requestPhonePermission;
return;
}
String mobileNumber = '';
// Platform messages may fail, so we use a try/catch PlatformException.
try {
mobileNumber = await MobileNumber.mobileNumber;
_simCard = await MobileNumber.getSimCards;
} on PlatformException catch (e) {
debugPrint("Failed to get mobile number because of '${e.message}'");
}
// If the widget was removed from the tree while the asynchronous platform
// message was in flight, we want to discard the reply rather than calling
// setState to update our non-existent appearance.
if (!mounted) return;
setState(() {
_mobileNumber = mobileNumber;
});
}
Widget fillCards() {
List<Widget> widgets = _simCard
.map((SimCard sim) => Text(
'Sim Card Number: (${sim.countryPhonePrefix}) - ${sim.number}\nCarrier Name: ${sim.carrierName}\nCountry Iso: ${sim.countryIso}\nDisplay Name: ${sim.displayName}\nSim Slot Index: ${sim.slotIndex}\n\n'))
.toList();
return Column(children: widgets);
}
This is working fine I can see the mobile number.
But now I need to search the number inside the list.
I checked some of the questions on SO to get it done but I am not good with lists.
I tried using some of the examples and comes up with below. But this is incorrect with so many errors.
var comparenumber = _simCard.map((SimCard sim).where((sim.number) => sim.number.toLowerCase().contains(mobile.toLowerCase()).toList();

Answer 1

If you want to search if the list has a number or part of a number (say the result would be true searching for 641 in a list that has a number 641-819-xxxx)
you can use this code
bool searchNumber(String number) {
return _simCard.where((element) => element.number.contains(number)).isNotEmpty;
}
if you want to search for an exact number match replace element.number.contains(number) with element.number == number as in dart == for strings compare the string value, not pointers as in Java for example.
So, what is where?
where is a function in the abstract class Iterable (and lists in dart are iterable) that take a predicate or a test function and returns an iterable that has only elements that match the predicate.
returned iterable can be collected to a list or you can use some other functions or properties directly on it like isNotEmpty in our case