Merge pull request #17026 from sk1418/impr-rm-el-list

[impr-rm-el-list] improvement remove the last element from a list

Author: theangrydev

core-java-modules/core-java-collections-array-list/pom.xml

@@ -45,9 +45,9 @@
     </build>
 
     <properties>
-        <maven-compiler-plugin.source>16</maven-compiler-plugin.source>
-        <maven-compiler-plugin.target>16</maven-compiler-plugin.target>
+        <maven-compiler-plugin.source>21</maven-compiler-plugin.source>
+        <maven-compiler-plugin.target>21</maven-compiler-plugin.target>
         <surefire.plugin.version>3.0.0-M3</surefire.plugin.version>
     </properties>
 
-</project>
+</project>

core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/java/list/RemoveFromList.java

@@ -0,0 +1,83 @@
+package com.baeldung.list.removeelement;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class RemoveElementFromAnArrayListUnitTest {
+    private List<String> getSportList() {
+        List<String> sports = new ArrayList<>();
+        sports.add("Football");
+        sports.add("Basketball");
+        sports.add("Baseball");
+        sports.add("Boxing");
+        sports.add("Cycling");
+        return sports;
+    }
+
+    @Test
+    void whenRemoveByIndex_thenCorrect() {
+        List<String> sports = getSportList();
+        assertThat(sports).hasSize(5).contains("Basketball");
+
+        sports.remove(1); //removing Basketball
+        assertThat(sports).hasSize(4).doesNotContain("Basketball");
+    }
+
+    @Test
+    void whenRemoveLastByIndex_thenCorrect() {
+        List<String> sports = getSportList();
+        List<String> expected = List.of("Football", "Basketball", "Baseball", "Boxing");
+
+        sports.remove(sports.size() - 1);
+        assertThat(sports).isEqualTo(expected);
+    }
+
+    @Test
+    void whenUsingJDK21RemoveLast_thenCorrect() {
+        List<String> sports = getSportList();
+        List<String> expected = List.of("Football", "Basketball", "Baseball", "Boxing");
+
+        sports.removeLast();
+        assertThat(sports).isEqualTo(expected);
+    }
+
+
+    @Test
+    void whenRemoveByElement_thenCorrect() {
+        List<String> sports = getSportList();
+        assertThat(sports).hasSize(5).contains("Basketball");
+
+        sports.remove("Basketball");
+        assertThat(sports).hasSize(4).doesNotContain("Basketball");
+    }
+
+    @Test
+    void whenRemovingWhileIterating_thenCorrect() {
+        List<String> sports = getSportList();
+        assertThat(sports).hasSize(5).contains("Basketball");
+
+        Iterator<String> iterator = sports.iterator();
+        while (iterator.hasNext()) {
+            if (iterator.next().equals("Basketball")) {
+                iterator.remove();
+                break;
+            }
+        }
+        assertThat(sports).hasSize(4).doesNotContain("Basketball");
+    }
+
+    @Test
+    void whenRemoveIf_thenCorrect() {
+        List<String> sports = getSportList();
+        assertThat(sports).hasSize(5).contains("Basketball");
+
+        sports.removeIf(p -> p.equals("Basketball"));
+
+        assertThat(sports).hasSize(4).doesNotContain("Basketball");
+    }
+}

core-java-modules/core-java-collections-array-list/src/test/java/com/baeldung/list/removeelement/RemoveElementFromAnArrayListUnitTest.java

@@ -47,7 +47,7 @@
         <module>core-java-12</module>
         <module>core-java-13</module>
         <module>core-java-15</module>
-        <module>core-java-collections-array-list</module>
+        <!--<module>core-java-collections-array-list</module> --> <!-- requires JDK 21 -->
         <module>core-java-collections-array-list-2</module>
         <module>core-java-collections-list-4</module>
         <module>core-java-collections-list-5</module>