From 72b6c786461b657b238944c8b9da4b378fbfc552 Mon Sep 17 00:00:00 2001
From: Kai Yuan <kent.yuan@Gmail.com>
Date: Sat, 16 Dec 2023 00:47:36 +0100
Subject: [PATCH] [last-iteration] detect the last iteration (#15414)

* [last-iteration] detect the last iteration

* [last-iteration] add core-java-loops module
---
 core-java-modules/core-java-loops/README.md   |  1 +
 core-java-modules/core-java-loops/pom.xml     | 16 ++++
 .../TheLastIterationInForEachUnitTest.java    | 93 +++++++++++++++++++
 core-java-modules/pom.xml                     |  1 +
 4 files changed, 111 insertions(+)
 create mode 100644 core-java-modules/core-java-loops/README.md
 create mode 100644 core-java-modules/core-java-loops/pom.xml
 create mode 100644 core-java-modules/core-java-loops/src/test/java/com/baeldung/loops/TheLastIterationInForEachUnitTest.java

diff --git a/core-java-modules/core-java-loops/README.md b/core-java-modules/core-java-loops/README.md
new file mode 100644
index 0000000000..5616cce48b
--- /dev/null
+++ b/core-java-modules/core-java-loops/README.md
@@ -0,0 +1 @@
+## Relevant Articles
diff --git a/core-java-modules/core-java-loops/pom.xml b/core-java-modules/core-java-loops/pom.xml
new file mode 100644
index 0000000000..c9ce86f54b
--- /dev/null
+++ b/core-java-modules/core-java-loops/pom.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-java-loops</artifactId>
+    <name>core-java-loops</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
+</project>
diff --git a/core-java-modules/core-java-loops/src/test/java/com/baeldung/loops/TheLastIterationInForEachUnitTest.java b/core-java-modules/core-java-loops/src/test/java/com/baeldung/loops/TheLastIterationInForEachUnitTest.java
new file mode 100644
index 0000000000..e8e20d4db7
--- /dev/null
+++ b/core-java-modules/core-java-loops/src/test/java/com/baeldung/loops/TheLastIterationInForEachUnitTest.java
@@ -0,0 +1,93 @@
+package com.baeldung.loops;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.IntStream;
+
+import org.junit.jupiter.api.Test;
+
+public class TheLastIterationInForEachUnitTest {
+
+    //@formatter:off
+    private static final List<String> MOVIES = List.of(
+      "Titanic",
+      "The Deer Hunter",
+      "Lord of the Rings",
+      "One Flew Over the Cuckoo's Nest",
+      "No Country For Old Men");
+    //@formatter:on
+
+    @Test
+    void whenUsingForEach_thenGetTheLastElementAfterTheLoop() {
+        String myLastMovie = "";
+        for (String movie : MOVIES) {
+            // ... work with movie
+            myLastMovie = movie;
+        }
+        assertEquals("No Country For Old Men", myLastMovie);
+    }
+
+    @Test
+    void whenLoopingWithIndexes_thenGetExpectedResult() {
+        int size = MOVIES.size();
+        String myLastMovie = null;
+        for (int i = 0; i < size; i++) {
+            String movie = MOVIES.get(i);
+            // ... work with movie
+            if (i == size - 1) {
+                myLastMovie = movie;
+            }
+        }
+        assertEquals("No Country For Old Men", myLastMovie);
+    }
+
+    @Test
+    void whenUsingIntStream_thenGetExpectedResult() {
+        int size = MOVIES.size();
+        final Map<Integer, String> myLastMovie = new HashMap<>();
+        IntStream.range(0, size)
+            .forEach(idx -> {
+                String movie = MOVIES.get(idx);
+                // ... work with movie
+                if (idx == size - 1) {
+                    myLastMovie.put(idx, movie);
+                }
+            });
+        assertEquals(1, myLastMovie.size());
+        assertTrue(myLastMovie.containsKey(size - 1));
+        assertTrue(myLastMovie.containsValue("No Country For Old Men"));
+    }
+
+    @Test
+    void whenUsingCounter_thenGetExpectedResult() {
+        int size = MOVIES.size();
+        String myLastMovie = null;
+        int cnt = 0;
+        for (String movie : MOVIES) {
+            // ... work with movie
+            if (++cnt == size) {
+                myLastMovie = movie;
+            }
+        }
+        assertEquals("No Country For Old Men", myLastMovie);
+    }
+
+    @Test
+    void whenUsingIterator_thenGetExpectedResult() {
+        String movie;
+        String myLastMovie = null;
+        for (Iterator<String> it = MOVIES.iterator(); it.hasNext(); ) {
+            movie = it.next();
+            // ... work with movie
+            if (!it.hasNext()) { // the last element
+                myLastMovie = movie;
+            }
+        }
+        assertEquals("No Country For Old Men", myLastMovie);
+    }
+}
\ No newline at end of file
diff --git a/core-java-modules/pom.xml b/core-java-modules/pom.xml
index d20a1650b9..f16cff3987 100644
--- a/core-java-modules/pom.xml
+++ b/core-java-modules/pom.xml
@@ -155,6 +155,7 @@
         <module>core-java-lang-syntax</module>
         <module>core-java-lang-syntax-2</module>
         <module>core-java-locale</module>
+        <module>core-java-loops</module>
         <module>core-java-networking</module>
         <module>core-java-networking-2</module>
         <module>core-java-networking-4</module>