.clear()
Published Feb 15, 2024
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The .clear()
method in Dart is used to remove all objects from a list, leaving an empty list in its place. This method is handy when we need to reset or clear the contents of a list, making it ready for new data. This method does not return any value.
Syntax
listName.clear();
Example
The .clear()
method only works on a growable list. If the list is a fixed-length list, then it throws an Unsupported operation
error and retains all objects in the list.
void main() {// Creates a growable list with 3 elements with a default value of each element set to 1final growableList = List<int>.filled(3, 1, growable: true);print(growableList);print(growableList.length);// Clears all objects from the growable listgrowableList.clear();print(growableList);print(growableList.length);// 'false' is the default value for growable in 'List.filled' constructorfinal fixedList = List<int>.filled(3, 3, growable: false);print(fixedList);// Throws an error for fixed listfixedList.clear();}
The output of the above code is:
[1, 1, 1]3[]0[3, 3, 3]Uncaught Error: Unsupported operation: clear
Notes:
- The
.clear()
method modifies the original list and does not create a new list.- After calling
.clear()
, the list will have a length of 0.- If the list is already empty, calling
.clear()
has no effect.- If the list is a fixed list, calling
.clear()
will throw an error.
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