Ways to iterate over a list

Issue: BAEL-2311
2018-11-29 11:58:12 -05:00
parent 1d0fab4252
commit 5812866573
2 changed files with 138 additions and 0 deletions
@@ -0,0 +1,71 @@
+package com.baeldung.java.list;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.ListIterator;
+
+import org.junit.Test;
+
+public class WaysToIterateUnitTest {
+
+    List<String> globalCountries = new ArrayList<String>();
+    List<String> europeanCountries = Arrays.asList("Germany", "Panama", "Australia");
+
+    @Test
+    public void whenIteratingUsingForLoop_thenReturnThreeAsSizeOfList() {
+        for (int i = 0; i < europeanCountries.size(); i++) {
+            globalCountries.add(europeanCountries.get(i));
+        }
+        assertEquals(globalCountries.size(), 3);
+        globalCountries.clear();
+    }
+
+    @Test
+    public void whenIteratingUsingEnhancedForLoop_thenReturnThreeAsSizeOfList() {
+        for (String country : europeanCountries) {
+            globalCountries.add(country);
+        }
+        assertEquals(globalCountries.size(), 3);
+        globalCountries.clear();
+    }
+
+    @Test
+    public void whenIteratingUsingIterator_thenReturnThreeAsSizeOfList() {
+        Iterator<String> countriesIterator = europeanCountries.iterator();
+        while (countriesIterator.hasNext()) {
+            globalCountries.add(countriesIterator.next());
+        }
+
+        assertEquals(globalCountries.size(), 3);
+        globalCountries.clear();
+    }
+
+    @Test
+    public void whenIteratingUsingListIterator_thenReturnThreeAsSizeOfList() {
+        ListIterator<String> countriesIterator = europeanCountries.listIterator();
+        while (countriesIterator.hasNext()) {
+            globalCountries.add(countriesIterator.next());
+        }
+
+        assertEquals(globalCountries.size(), 3);
+        globalCountries.clear();
+    }
+
+    @Test
+    public void whenIteratingUsingForEach_thenReturnThreeAsSizeOfList() {
+        europeanCountries.forEach(country -> globalCountries.add(country));
+        assertEquals(globalCountries.size(), 3);
+        globalCountries.clear();
+    }
+
+    @Test
+    public void whenIteratingUsingStreamForEach_thenReturnThreeAsSizeOfList() {
+        europeanCountries.stream().forEach((country) -> globalCountries.add(country));
+        assertEquals(globalCountries.size(), 3);
+        globalCountries.clear();
+    }
+}