The checkedList() method of java.util.Collections class is used to return a dynamically typesafe view of the specified list.
The returned list will be serializable if the specified list is serializable.
Since null is considered to be a value of any reference type, the returned list permits insertion of null elements whenever the backing list does.
Syntax:
public static List checkedList(List list, Class type)
Parameters: This method takes the following arguments as a parameters:
- list – the list for which a dynamically typesafe view is to be returned
- type – the type of element that list is permitted to hold
Return Value: This method returns a dynamically typesafe view of the specified list
Below are the examples to illustrate the checkedList() method
Example 1:
// Java program to demonstrate // checkedList() method // for String value import java.util.*; public class GFG1 { public static void main(String[] argv) throws Exception { try { // creating object of List<String> List<String> arlst = new ArrayList<String>(); // Adding element to arlst arlst.add( "A" ); arlst.add( "B" ); arlst.add( "C" ); arlst.add( "TajMahal" ); // printing the arrlist System.out.println( "List: " + arlst); // create typesafe view of the specified list List<String> tslst = Collections .checkedList(arlst, String. class ); // printing the arrlist after operation System.out.println( "Typesafe view of List: " + tslst); } catch (IllegalArgumentException e) { System.out.println( "Exception thrown : " + e); } } } |
List: [A, B, C, TajMahal] Typesafe view of List: [A, B, C, TajMahal]
Example 2:
// Java program to demonstrate // checkedList() method // for Integer value import java.util.*; public class GFG1 { public static void main(String[] argv) throws Exception { try { // creating object of List<Integer> List<Integer> arlst = new ArrayList<Integer>(); // Adding element to arlst arlst.add( 20 ); arlst.add( 30 ); arlst.add( 40 ); arlst.add( 50 ); // printing the arrlist System.out.println( "List: " + arlst); // create typesafe view of the specified list List<Integer> tslst = Collections .checkedList(arlst, Integer. class ); // printing the arrlist after operation System.out.println( "Typesafe view of List: " + tslst); } catch (IllegalArgumentException e) { System.out.println( "Exception thrown : " + e); } } } |
List: [20, 30, 40, 50] Typesafe view of List: [20, 30, 40, 50]
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