From f13baaf5d27b6108256da6a7842accd91f0fec86 Mon Sep 17 00:00:00 2001 From: Diegom203 <153622681+Diegom203@users.noreply.github.com> Date: Thu, 14 Mar 2024 20:58:01 +0200 Subject: [PATCH] baeldung-articles : BAEL-7500 (#16084) * baeldung-articles : BAEL-7500 Adding elements to a collection during iteration. * I modify the ListIterationUnitTest.java --- .../listiteration/ListIterationUnitTest.java | 71 +++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 core-java-modules/core-java-collections/src/test/java/com/baeldung/listiteration/ListIterationUnitTest.java diff --git a/core-java-modules/core-java-collections/src/test/java/com/baeldung/listiteration/ListIterationUnitTest.java b/core-java-modules/core-java-collections/src/test/java/com/baeldung/listiteration/ListIterationUnitTest.java new file mode 100644 index 0000000000..2f1b2cc083 --- /dev/null +++ b/core-java-modules/core-java-collections/src/test/java/com/baeldung/listiteration/ListIterationUnitTest.java @@ -0,0 +1,71 @@ +package com.baeldung.listiteration; + +import org.junit.jupiter.api.Test; + +import java.util.*; +import java.util.stream.Collectors; +import java.util.stream.Stream; + +import static org.junit.jupiter.api.Assertions.assertIterableEquals; + +public class ListIterationUnitTest { + + List programmingLanguages = new ArrayList<>(List.of("Java", "Python", "C++")); + List numbers = new ArrayList<>(List.of(1, 2, 3)); + + @Test + public void givenStringList_whenAddElementWithListIterator_thenModifiedList() { + ListIterator listIterator = programmingLanguages.listIterator(); + while (listIterator.hasNext()) { + String language = listIterator.next(); + if (language.equals("Python")) { + listIterator.add("JavaScript"); + } + } + + assertIterableEquals(Arrays.asList("Java", "Python", "JavaScript", "C++"), programmingLanguages); + } + + @Test + public void givenNumericalList_whenMultiplyElementWithListIterator_thenModifiedList() { + ListIterator listIterator = numbers.listIterator(); + while (listIterator.hasNext()) { + int num = listIterator.next(); + if (num == 2) { + listIterator.add(num * 10); + } + } + assertIterableEquals(Arrays.asList(1, 2, 20, 3), numbers); + } + + @Test + public void givenStringList_whenAddElementWithEnhancedForLoopAndCopy_thenModifiedList() { + List copyOfWords = new ArrayList<>(programmingLanguages); + for (String word : copyOfWords) { + programmingLanguages.add(word.toUpperCase()); // Modified: Convert to uppercase + } + assertIterableEquals(Arrays.asList("Java", "Python", "C++", "JAVA", "PYTHON", "C++"), programmingLanguages); + } + + @Test + public void givenNumericalList_whenMultiplyElementWithEnhancedForLoopAndCopy_thenModifiedList() { + List copyOfNumbers = new ArrayList<>(numbers); + for (int num : copyOfNumbers) { + numbers.add(num * 2); + } + assertIterableEquals(Arrays.asList(1, 2, 3, 2, 4, 6), numbers); + } + + @Test + public void givenStringList_whenConvertToUpperCaseWithJava8Stream_thenModifiedList() { + programmingLanguages = programmingLanguages.stream().map(String::toUpperCase).collect(Collectors.toList()); + assertIterableEquals(Arrays.asList("JAVA", "PYTHON", "C++"), programmingLanguages); + } + + @Test + public void givenNumericalList_whenMultiplyByThreeWithJava8Stream_thenModifiedList() { + numbers = numbers.stream().map(num -> num * 3).collect(Collectors.toList()); + assertIterableEquals(Arrays.asList(3, 6, 9), numbers); + } + +}