Java Collections - Collections.addAll() Examples

Java Collections Java Java API 

Class:

java.util.Collections

Method:

@SafeVarargs
public static <T> boolean addAll(Collection<? super T> c,
                                              T... elements)

Adds all of the specified elements to the specified collection.

This method loops through each specified element and add to the collection individually:

boolean result = false;
for (T element : elements)
        result |= c.add(element);
    return result;

Examples

package com.logicbig.example.collections;

import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

public class AddAllExample {

    public static void main(String... args) {
        Set<Integer> set = new HashSet<>();
        boolean b = Collections.addAll(set, 1, 2, 3, 4, 5);
        System.out.println(b);
        System.out.println(set);
    }
}

Output

true
[1, 2, 3, 4, 5]