BAEL-6837 Add example code for getting the first item from a Set

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Sam Gardner 2023-08-02 12:05:17 +01:00
parent d4fec3ad45
commit b5fef8d2b5
1 changed files with 35 additions and 0 deletions

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package com.baeldung.firstitemfromset;
import static org.junit.Assert.assertEquals;
import java.util.Arrays;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Optional;
import java.util.Set;
import org.junit.Test;
public class GetFirstItemFromSetUnitTest {
@Test
public void givenASet_whenUsingIterator_thenRetrieveAnItem(){
Set<Integer> set = new LinkedHashSet<>(Arrays.asList(1, 2, 3, 4, 5));
Iterator iterator = set.iterator();
if(iterator.hasNext()){
int retrieved = (int) iterator.next();
assertEquals(retrieved, 1);
}
}
@Test
public void givenASet_whenUsingStreams_thenRetrieveAnItem(){
Set<Integer> set = new LinkedHashSet<>(Arrays.asList(1, 2, 3, 4, 5));
Optional<Integer> optional = set.stream().findFirst();
if(optional.isPresent()){
int retrieved = optional.get();
assertEquals(retrieved, 1);
}
}
}