description

# singleWhere method Null safety

String singleWhere (

1. bool test(
   1. String value
   ),
2. {String orElse(
   )}

)
inherited

Returns the single element that satisfies `test`.

Checks elements to see if `test(element)` returns true. If exactly one element satisfies `test`, that element is returned. If more than one matching element is found, throws StateError. If no matching element is found, returns the result of `orElse`. If `orElse` is omitted, it defaults to throwing a StateError.

## Implementation

    String singleWhere(bool test(String value), {String orElse()?}) =>
        readClasses().singleWhere(test, orElse: orElse);