Flutter FirstWhere Bad State No Element
When you encounter the “Bad state: No element” error while using the firstWhere
method in Flutter, it means that the method was unable to find any matching element in the list based on the provided condition.
The firstWhere
method retrieves the first element in the list that satisfies the provided condition. If no element satisfies the condition, it will throw the “Bad state: No element” error.
Here’s an example to understand this error:
var myList = [1, 2, 3, 4, 5];
var result = myList.firstWhere((element) => element > 6);
print(result);
In this example, the firstWhere
method is used to find the first element greater than 6 in the myList
. However, since there is no element greater than 6 in the list, it will throw the “Bad state: No element” error.
To handle this error, you can provide a default value to be returned in case no element satisfies the condition. This can be achieved by using the orElse
parameter of the firstWhere
method. Here’s an updated example:
var myList = [1, 2, 3, 4, 5];
var result = myList.firstWhere((element) => element > 6, orElse: () => -1);
print(result);
In this updated example, the orElse
parameter is used to specify the default value (-1) to be returned if no elements satisfy the condition. So instead of throwing the error, it will return -1 as the result.
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