Java list addAll null

java.util.Collections.addAll() Method

Description

The addAll(Collection<? super T>, T..) method is used to add all of the specified elements to the specified collection.

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java.util.Collections.addAll() Method
Description
Declaration
Return Value
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Declaration

Following is the declaration for java.util.Collections.addAll() method.

public static <T> boolean addAll(Collection<? super T> c, T.. a)

Parameters

c This is the collection into which elements are to be inserted.
a This is the elements to insert into c

Return Value

The method call returns 'true' if the collection changed as a result of the call

Exception

UnsupportedOperationException This is thrown if c does not support the add method.
NullPointerException This is thrown if elements contains one or more null values and c does not support null elements.
IllegalArgumentException This is thrown if some aspect of a value in elements prevents it from being added to c.

Example

The following example shows the usage of java.util.Collections.addAll()

Live Demo

package com.tutorialspoint; import java.util.*; public class CollectionsDemo { public static void main(String args[]) { // create array list object List arrlist = new ArrayList(); // populate the list arrlist.add("A"); arrlist.add("B"); arrlist.add("C"); System.out.println("Initial collection value: "+arrlist); // add values to this collection boolean b = Collections.addAll(arrlist, "1","2","3"); System.out.println("Final collection value: "+arrlist); } }

Let us compile and run the above program, this will produce the following result.

Initial collection value: [A, B, C] Final collection value: [A, B, C, 1, 2, 3]

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